Pipelines 2014: From Underground to the Forefront of Innovation and Sustainability

Aging pipeline infrastructure and limited funding for pipeline maintenance efforts make condition assessment an essential function in managing large-diameter pipeline assets for water agencies. Many of these pipelines are prestressed concrete cylinder pipe (PCCP) and, therefore, are subject to an elevated risk of failure attributable to prestressed wire breaks and continued corrosion of steel cylinders. Major water agencies must emphasize assessing and monitoring the PCCP pipelines' condition. Condition assessments should include (1) determining the pipeline's structural condition by considering the number of wire breaks and the external and internal loads on the pipeline, (2) ranking the pipeline's condition, and (3) prioritizing maintenance needs. Based on past research supported by the PCCP Users Group and the American Concrete Pressure Pipe Association (ACPPA), the use of risk curves in PCCP asset management has been successfully demonstrated in the existing literature. However, given the complex structural analysis procedures required for the design of PCCP and the development of appropriate representations for wire break conditions, analysis tools for creating such risk curves have not been widely developed for practical applications. This paper presents a Microsoft Excel spreadsheet-based risk assessment tool developed by the primary author to perform structural analyses and to create risk curves based on condition assessment findings, including wire breaks detected through electromagnetic data and corrosion damage to cylinders obtained from internal and external pipeline inspection. The spreadsheet tool uses the structural analysis approach outlined in the current American Water Works Association (AWWA) C304 standard and historical C301 and C304 standards. The paper also presents an example of the tool's application to a risk-based condition assessment program.

CH2M HILL has recently performed several successful condition assessments of critical ocean wastewater outfall structures. Assessing the structural condition and hydraulic performance of ocean wastewater outfalls represents some of the greatest challenges to agencies controlling publicly owned infrastructure. These structures are extraordinarily difficult to access, require a carefully executed inspection plan, and often require advanced technologies to gather the data needed to complete a successful assessment. In many cases these condition assessments represent the first attempt to inspect the existing infrastructure since their original installation and, as such, will form the baseline for future inspections. This paper presents an overview of strategies that were implemented (or will be implemented) for comprehensive assessments at four outfall locations. These locations and strategies are briefly summarized as follows: Anchorage, AK—Inspection and assessment of the Anchorage Water and Wastewater Utility (AWWU) 84-120 in. Asplund wastewater treatment plant (WWTF) 900 ft outfall and control structure existing in an area with tidal fluctuations of up to 35 ft. Honolulu, HI—Preinspection and assessment of the City and County of Honolulu (CCH) Honouliuli WWTP Barber's Point outfall system representing nearly 19,700 ft of 84 in. RCP (both land and ocean portions). Port Townsend, WA—Inspection and assessment of 840 ft of submerged 18-20 in. outfall and diffuser structure performed in two stages. Ponce, Puerto Rico—Internal and external inspection and rehabilitation of the PRASA Ponce Regional WWTP outfall structure (21,000 ft of 48 in. pipeline). Each project required overcoming unique challenges and conditions that can be applied to a broad range of ocean outfalls. This paper reviews the work plans developed and implemented to leverage the right people, equipment, technologies, and science. The goal of each assessment was to create a sustainable road map for this wastewater infrastructure.

Without good pipe-condition data, water main renewal cannot be optimized. Poor information about the integrity and life expectancy of water mains results in three basic asset management errors: (1) Comparatively strong mains are often discarded, because they are perceived to be weak. (2) Renewal of some mains occurs too late, resulting in repairs that were avoidable. (3) Rehabilitation methods are often inappropriately applied, either wasting money and producing an inferior product, or failing to use the residual strength of the host main and spending too much In-pipe nondestructive examination (NDE) tools have existed for many years, but these tools are seldom used for small-diameter mains, partly because they are considered too expensive. Many utilities would rather invest in new pipe than in testing old pipe. A large part of the cost of an in-pipe NDE assessment entails inserting and extracting these devices within an operating water system. Moreover, when these NDE tools are used, no guidelines exist for interpreting and applying the data. Instead of using NDE tools, the conditions of mains are usually inferred from indirect data: break history, age, soil conditions, and limited examinations of the pipes. Two Water Research Foundation (WaterRF) projects are underway, aimed at practical applications of current NDE technology on small water mains. Project 4471 proposes to use NDE in a nondisruptive manner to "sample" pipe in a system, then apply the information to infer the condition of similar pipes. Project 4473 goes a step further, proposing to combine the assessment, engineering, and rehabilitation of water mains into a single product delivery. This presentation will discuss the findings and recommendations of the research performed to date, including the results of side-by-side applications of several technologies along a main in Los Angeles.

The City of Fort Worth Water Department has undertaken a comprehensive program utilizing multisensor inspection (MSI) technology to inspect its entire large-diameter sanitary sewer interceptor system. As the program approaches 50% complete, this paper presents the techniques used for condition assessment and how the condition of the pipes and location of debris were translated into estimates of remaining useful life, efficiently targeted large-diameter cleaning, and repair/replacement recommendations for long-term asset management. Assessment techniques included laser profiling, sonar, and high-definition televising. The Fort Worth project is considered one of the largest multisensor interceptor condition assessment projects in the world. The interceptor system contains 262 miles of pipelines ranging from 24 in. to 96 in. diameter. Original pipe materials were primarily reinforced concrete with some vitrified clay. More recent pipe materials were fiberglass and plastic direct burial and liners. To date more than 50 different pipe specifications have been identified and included in the remaining useful life (RUL) matrix. Expectations based on age and pipe materials in many cases were contradicted by actual measurements of pipe wall loss and condition. Utilizing the RUL Matrix, measured remaining wall thickness, and calculated deterioration rates per year, the Fort Worth Water Department is able to identify pipe segments that require near-term remediation and optimize future pipe segment inspections.

A condition assessment program should be an integral part of a utility's strategy for managing repair and replacement of its large-diameter piping. Using nondestructive condition assessment and performance analysis can prolong the useful life of piping, reduce the risk of catastrophic failure, allow for target rehabilitation, and significantly reduce the community disruption and capital cost of pipeline replacement projects. Tampa Bay Water is a wholesale water provider with more than $1 billion in assets and more than 100 miles of large-diameter piping. Tampa Bay Water's regional water delivery system supplies quality water to 2.3 million customers to six member governments: the cities of Tampa, St. Petersburg, New Port Richey, and Hillsborough, Pinellas, and Pasco Counties. The regional water system comprises groundwater and surface water sources, an off-stream storage reservoir, a seawater desalination plant and a collection of treatment facilities pipes and pumps. The focus of the agency has recently shifted from completing new water supply projects, to repairing and maintaining its large and diverse wholesale water treatment and conveyance system.

A 30-in. diameter steel underground natural gas transmission line owned and operated by the Pacific Gas and Electric Company (PG&E) suddenly ruptured in San Bruno, California on September 9, 2010. The subsequent explosion and fire resulted in the loss of eight lives, injuries to 67 individuals, and the total destruction of 38 homes. Additionally, 70 homes sustained damage, and 18 homes adjacent to the destroyed properties were left uninhabitable. A thorough investigation ensued to determine the actual cause of this tragic event. The National Transportation Safety Board's (NTSB) investigation concluded that the rupture of the pipeline was a result of a fracture that originated in the partially welded longitudinal seam of one of six short pipe sections, which are known in the industry as "pups." The fabrication of five of the pups in 1956 would not have met generally accepted industry quality control and welding standards then in effect, indicating that those standards were either overlooked or ignored. The San Bruno incident ranks as the most significant natural gas pipeline incident in terms of loss of life and property in recent years. This paper provides an overview of this tragic event and discussion of the investigation process.

Two utilities, the Portland Water Bureau of Oregon and WaterOne of Kansas, provide water supply to more than 400,000 customers. Both utilities have more than 2,000 miles of pipe. Portland Water has more cast iron pipe and low break rates, due to a somewhat noncorrosive environment. WaterOne has more ductile iron and cast iron pipe, with a corrosive soil environment. WaterOne has much higher break rates. Most pipes in the Portland Water system are run to failure; a pipe replacement program is focused primarily on those pipe segments with a history of low consequence leaks and breaks. WaterOne also has a pipe replacement program but break history is only one of eight criteria. Both utilities use condition assessment for the management of high-consequence pipes. Portland Water uses primarily leak detection. WaterOne uses methods to detect pipe wall thickness lost. A business case methodology has been used to justify condition assessment. Portland Water has justified a major condition assessment effort by considering the risk cost of catastrophic failure. WaterOne has justified a major condition assessment by considering the value of selective replacement of the most corroded sections of a pipe only and deferral of the remainder of the pipe.

The consequences of failure for prestressed concrete cylinder pipe (PCCP) are usually very high due to its large diameter and high internal pressure. To monitor these critical pipes, acoustic fiber optic (AFO) monitoring systems are now being used to observe the real-time breakage of prestressing wires in the pipe. However, if PCCP is not adequately prestressed, the wire break does not generate obvious acoustic noise that the AFO system is able to capture. The "unrecorded" wire breaks or inadequate prestress, together with other defects (such as corroded cylinder), can cause the failure of the pipe. This paper presents the results of an analysis conducted for a PCCP with inadequate prestress that failed without warning from the AFO system. The findings of this research will improve the current understandings of PCCP with inadequate prestress and help utilities better manage PCCPs with similar conditions. A 60-in. PCCP within the Washington Suburban Sanitary Commission (WSSC) jurisdiction failed without warning from the installed AFO system. This failure was unanticipated to because the number of broken wires recorded by AFO system was not severe enough to cause pipe failure under normal conditions. This failure also revealed the limitation of this technology in PCCP management, as the number of broken wires recorded is not enough to evaluate the pipe condition. Some other critical factors can also cause the failure of the pipe. Forensic investigations showed that the pipe had inadequate prestress in the failure area and that the water corroded the wires and cylinder, which the AFO system cannot detect. In this paper, a finite element (FE) model is developed to analyze the performance of the pipe with inadequate prestress in the prestressing wire. Scenarios such as prestressing wire with full prestress, no prestress, no prestressing wires, and with six broken wires are simulated to better understand the structural integrity of the pipe. The model considers loadings such as internal pressure and the weight of soil and pipe. It also considers pipe components such as concrete core, steel cylinder, prestressing wires, saddle steel, and mortar coating.

The City of Atlanta Department of Watershed Management has been systematically improving the knowledge of its asset base for the last few years. The Sewer System Evaluation Surveys (SSES) program involved inspection of 1,600 miles of sanitary sewer pipelines, took a decade, and was recently completed. The department has now begun to make advancements in trying to gather knowledge of its drinking water systems through a valve and hydrant location program and GIS mapping of drinking water lines. The classical approach to asset management suggests that an organization work on knowing what asset it has before beginning condition assessment programs. Atlanta is finding that this approach of developing a comprehensive asset register is too expensive, time consuming, and impractical for an organization that needs to be constantly thinking about the best ways to allocate capital funding and to make decisions on asset renewal, rehabilitation, and replacement. Moreover, the ready availability of robust/current operations and maintenance data (O&M) always tends to be a challenge. In this paper, we show how the City of Atlanta is developing models based on risk and criticality evaluations with available data for its drinking water and sanitary sewer pipelines. Atlanta's approach is to evolve a model that is continually updated as the data quality gets better because of targeted efforts in that space. Meanwhile, the city uses heuristics (rules of thumb), targeted risk and consequence of failure scoring, and sensitivity analysis of the scoring results to create lists of assets that can then be subject to conventional condition assessment programs. Because conventional condition assessment programs tend to be invasive and expensive, it is incumbent on Atlanta, which like most utilities is fiscally constrained, to develop desktop models that can serve as cost-effective simulations for narrowing down the number of miles of pipelines (both drinking water and wastewater) that need to be targeted for traditional condition assessment. This paper will detail the evolution of this microtargeting approach, based on available data, and then detail the mechanisms used for smoothing the data. Development of a robust and sustainable long-term asset management program for pipelines requires the ability to evaluate knowledge about a system's condition using mechanisms that are data driven and yet easily accessible. This paper will look at how Atlanta's Department of Watershed Management is developing an iterative approach to system condition information management and decision making.

Denver Water has embarked on a decade-long process of renewing its North System facilities. These facilities include reservoirs, raw water transmission mains, and the Moffat Water Treatment Plant. A key element of this system is parallel raw water transmission mains: Conduit 16, a 75-year-old 42-in. diameter reinforced concrete pressure pipeline, predominately cylinder-type, and Conduit 22, a 60-year-old 54-in. diameter reinforced concrete cylinder pressure pipeline. These 8.5 mile long pipelines were originally constructed across virtually open country, but now traverse highly developed commercial and residential properties with extreme encroachment on the existing easement. Denver Water had an $80 million decision to make: determine if these conduits could continue to function as part of its renewed North System or if one or both would need to be replaced or rehabilitated. To answer this question, the company undertook a comprehensive program including (1) condition assessment of both pipelines to determine potential future service life, (2) hydraulic modeling to validate existing pipeline capacity with and without existing pressure-reducing valves, (3) structural analysis to determine the current safe operating pressures for both pipelines, (4) analysis to determine hydraulic capacity of alternative pipelines alone and in combination with the existing conduits, (5) alternative routing analyses to determine if a less encumbered route was feasible and cost effective, and (6) examination of the costs and risks associated with the significant public impacts associated with replacement or rehabilitation within the existing corridor. The process of combining the probabilistic elements of assessment, quantitative elements of structural and hydraulic engineering analysis, and the qualitative elements of public impacts associated with alternative routing in selection of a preferred alternative will provide several insights for those encountering similar significant decisions on critical pipelines in their future systems. The selected alternative is currently under design and is scheduled for construction in 2015.

The Trinity River Authority of Texas (TRA) recently completed a comprehensive condition assessment of 8.8 miles of 30-in. bar-wrapped pipe (BWP). The assessment utilized an inline free-swimming acoustic tool, an inline free-swimming enhanced electromagnetic tool, transient pressure monitoring, and nonlinear finite element analysis (FEA) of the steel cylinder corrosion and broken bar wraps. This project is one of the first and perhaps most comprehensive assessments of a BWP transmission main in the industry. The pipeline is a critical link in the reliable delivery of drinking water to five cities in the Dallas-Fort Worth Metroplex, and it had been slated for replacement due to its age, previous failures, inability to be shut down for repairs, and the need for additional capacity. However, as the future projected water demands decreased, the additional capacity that was driving the immediate replacement of the pipeline was not necessary. TRA decided to evaluate the possibility of keeping the pipeline in service by performing a comprehensive hydraulic, leak, and condition assessment. The inspection and FEA analysis found that the majority of the pipes (93%) are in good structural condition and 6% of the pipes in fair condition, leaving only 14 pipes (1%) that need to be addressed in the near term. To confirm the efficacy of the condition assessment strategies, TRA excavated three test pits and performed external evaluation of the pipe at locations where damage was reported. This paper will present the inspection results including the leaks, gas pockets, broken bars, and cylinder corrosion detected during the field inspection work. Based on these results, TRA successfully deferred a $25 million capital replacement project by managing the pipeline as individual, 36-ft pipe assets.

The Anchorage Water and Wastewater Utility (AWWU) owns and operates 1940s vintage cast iron water mains that are within the Alaska Railroad yard complex. These 10-, 12-, and 16-in. mains are some of the oldest mains within AWWU's distribution system. Previous failures on the 10-in. main raised concern about the integrity of the 12- and 16-in. mains. AWWU retained Pipeline Inspection and Condition Analysis Corporation (PICA) to perform condition assessment of the mains to determine appropriate rehabilitation or replacement timing. The use of PICA's technology required the mains to be taken out of service. Due to the location of the mains adjacent to and directly under active railroad tracks, temporary water system construction would have been extremely costly to construct. Because temporary water could not be provided, work was performed in segments during limited six- to eight-hour windows to work around railroad maintenance and tourism company schedules. The physical location and limited time constraints provided challenges to AWWU and PICA's performance of the work. Through early planning, stakeholder coordination, and the ability to adapt to changes, the inspections were performed over a one-week period in late August and early September 2013 and produced data that validated the need to not only replace the 10-in. line, but also replace or rehabilitate portions of the 12- and 16-in. mains.

On February 5, 1999, a 96-in. diameter pipeline failed catastrophically, funneling 38 million gallons of water through a half-mile square residential area in just 90 minutes, causing extensive property damage and resulting in 12 homes being condemned. The City vowed to the community that it would begin performing annual inspections of this and similar pipelines. Within months of the catastrophic failure, Tucson began networking with other agencies that operated and maintained similar pipeline infrastructure. By February 2000, Tucson implemented its own condition assessment program, named the Pipeline Protection Program (PPP), and it evolved to become one of the more advanced predictive and preventive maintenance programs for prestressed concrete cylinder pope (PCCP). Beginning with routine internal visual pipeline inspections, internal electromagnetic surveys, and hydrophone arrays and quickly advancing to acoustic fiber optics (AFO), Tucson has managed to avoid any catastrophic failures, yet had a very close call when it identified a recent incipient failure of a 96-in. pipeline. Alerted by Tucson's AFO system, the 96-in. pipeline had all the potential to surpass the damage and destruction experienced in the $5 million 1999 failure. This technical paper shares some of the biggest challenges faced when building and implementing a condition assessment program for large-diameter pipelines and highlights successes, including how Tucson's most recent investment in AFO paid off big for Tucson.

Broadband electromagnetic (BEM) testing is being used as part of corrosion control/condition assessment practices on pipelines and force mains. The tool provides a means of measuring wall thickness of piping. Determining the level of internal and external corrosion is critical to evaluating assets' remaining useful life. The pros and cons of using BEM in the field will be discussed. The pipe materials include welded steel, ductile iron, and cast iron pipe. Case studies and lessons learned will be explained. In the trench testing techniques and limitations will be highlighted. The practice of using BEM testing in conjunction with or in lieu of ultrasonic testing will be evaluated.

The South Tahoe Public Utility District (STPUD) owns and operates an effluent pumping and pipeline system consisting of two large effluent pump stations and more than 132,000 lineal ft of effluent pipeline facilities. Constructed in 1967, the C-line segment is approximately 56,400 lineal ft in length, drops more than 2,100 vertical ft and has a diameter ranging from 18 to 21 in. The original pipeline material is welded steel (AWWA C200) with a cement mortar lining and coal tar epoxy coating. Performing a strategic and thorough condition assessment is a critical element for determining the interior and exterior condition and the structural integrity of an existing pipeline. However, STPUD budgetary funds were not sufficient to conduct a complete assessment of the entire length of the C-line. Therefore, the project team developed a collaborative approach to identifying critical sections of the pipeline for evaluation and completing the fieldwork that maintained budget while providing useful information for determining future rehabilitation and replacement for approximately 20% of the C-line.

The failure of prestressed concrete cylinder pipe (PCCP) is often due to poor bedding installation. Pipe bedding conditions that do not meet specifications can lead to a significantly overstressed concrete core. This overstress condition can lead to cracking of the mortar coating, which will result in depassivation of the prestressing wire leading to corrosion. Depending on the degree of overstress, pipe failure may occur in 40 years or less. In extreme conditions where the pipe is placed directly on bedrock or shot rock, point loads occur, which leads to mortar cracking, and pipe failure can take place in a shorter time frame. While it is not possible to directly measure pipe bedding conditions, it is possible to detect the concrete core deteriorated properties caused by poor bedding with sonic/ultrasonic nondestructive testing. This testing can detect concrete core microcracking, cracking, and coating and cylinder delamination.

Direct condition assessment (DCA) of pipelines in water, waste water, oil, or gas service is growing in popularity due to the fact that asset managers need to know the condition of their pipelines, in detail, to maintain them and extend their life. Knowing which DCA tool is best for a given type of pipeline is an important step in selecting the best technology. This paper discusses the attributes of in-line inspection (ILI) tools that utilize remote field technology (RFT), ultrasonic (UT), electromagnetic acoustic technology (EMAT), and magnetic flux leakage (MFL) tools and discusses the strengths and limitations of each.

Halton Region (the Region) is located west of the City of Toronto and is part of the Greater Toronto Area (GTA). It is one of the fastest growing municipalities in the GTA with the majority of the population residing in the following four urban areas: Oakville, Burlington, Milton, and Halton Hills. AECOM recently completed the Region's Sustainable Halton Master Plan that lays out sustainable growth and servicing strategies to meet the population and employment needs to the year 2031. As part of the Region's sustainable growth strategy, the Dundas Street corridor is key to developing the north end of the Town of Oakville. To facilitate this growth, AECOM designed the 1,000 L/s North Oakville Wastewater Pump Station (WWPS), twin 750 mm forcemains and 1,200 mm sanitary sewer, which was constructed in a 2,100 mm tunnel. This paper focuses on the corrosion reduction measures developed during the design phase of the project and implementation issues that occurred during construction. The 1,200 mm sanitary sewer and twin 750 mm forcemains carry sewage 2.6 km from the newly constructed North Oakville WWPS at Neyagawa Boulevard to Third Line on Dundas Street West. Design of the sanitary sewer and forcemains incorporates one cast-in-place manhole at Third Line and three precast manholes integrated as part of the tunnel shafts. The 450 m, 1,200 mm sanitary sewer was mostly constructed by tunnel methods. In addition to the sanitary sewer, twin 2.2 km, 750 mm diameter forcemains were constructed from the new North Oakville WWPS outletting into the new 1,200 mm diameter sanitary sewer on Dundas Street. The connection of the twin 750 mm forcemains to the 1,200 mm sanitary sewer was by two 7.1 m high drop structures (one for each forcemain). To reduce the release of odors and hydrogen sulfide (H2S), the project team investigated various design options that included several types of drop structures (e.g., vortex, baffle, vertical), various materials and coatings to resist concrete corrosion, and other site-specific options. Selection of the final drop structure design and construction materials was based on the team's previous large drop structure experience and input from various suppliers. The vortex drop structure was selected and designed to minimize maintenance and extend the life of the structure and downstream sewer. The design included the use of specialized concrete additives and coatings within the chambers in addition to a liner for the tunnel downstream of the chambers. The drop structure downstream pipe was protected from corrosion by T-Lock and Arrow-Lock. During construction, issues addressed included the adhesion of the specialized coating onto the chamber and release of the tunnel pipe liner at the interface between the tunnel and one of the chambers. The team worked with the suppliers and contractor to successfully resolve these issues.

The Region of Peel (Region) has implemented a replacement program for its ductile iron (DI) pipe 300 mm and smaller due to the high number of failures experienced with this type of pipe. As part of the replacement program, a section of the distribution system was scheduled to be abandoned in Caledon, Ontario, during the spring of 2013. The abandoned main was made of 300 mm cement mortar-lined DI pipe, Class 52. Prior to abandoning the main the Region of Peel chose to conduct field trials on a 150 m section of the water main using multiple inspection platforms and technologies being developed by Pure Technologies (Pure). The first field inspection was completed while the pipeline remained in service using the Sahara II platform, which simultaneously deploys closed-circuit television (CCTV), acoustic leak detection, and acoustic pipe wall assessment. A second inspection was conducted, after the line was taken out of service, utilizing a magnetic flux leakage (MFL) tool capable of penetrating a mortar lining. Overall, the inspections determined that the line was in great shape with only minor isolated areas of wall loss. Individual pipes identified to have defects were removed from the ground and taken to the shop for validation testing. Collaboration between pipeline owners and technology suppliers to conduct field trials is an important step in developing new technologies. Lessons learned from performing the field trial will be discussed.

In July of 2011, the Rundle Feedermain, a 24-in. (600-mm) C303 concrete bar-wrapped pipe (BWP) transmission main, failed in a residential neighborhood in the City of Calgary (the City). Residential development had cropped up around the feedermain since its construction in 1973. Although the main is located in an easement, the exact break location was 9 ft (3 m) west of a residential property line. This increased the main's consequence of failure, as additional ruptures may cause serious damage to private property. To return the Rundle Feedermain to operation, the City commissioned Pure Technologies (Pure) to complete an emergency inspection of the pipeline. Pure mobilized available inspection platforms to examine the line upstream and downstream of the failure location to ensure that no other pipe sections were at risk of rupture. The inspection used a robotics platform equipped with Pure's electromagnetic (EM) technology, which is able to identify broken bars and broad areas of cylinder corrosion in BWP. The emergency assessment identified four additional areas of distress and allowed the City to repair a second section of BWP that was likely to fail had the pipeline returned to operation. After the successful inspection of the Rundle Feedermain, the City of Calgary began incorporating BWP inspection into its biannual feedermain condition assessment program. Due to this shift in focus, in August of 2013 the City excavated one section of 30-in. (750-mm) BWP that was identified as badly distressed during the inspection program. The excavation verified that the pipe had broken bars and cylinder corrosion and was a candidate for near-term failure if left in operation. Due to the various operating conditions encountered in the program and with the City's cooperation, Pure has been able to refine and improve BWP inspection technology and apply it to multiple inspection vehicle platforms to assess the City's BWP mains. Through condition assessment, the City is able to identify and repair isolated damaged pipe sections on otherwise serviceable pipelines. This prevents unnecessary and expensive main rehabilitation or replacement, while renewing the condition of the City's critical large-diameter pipeline assets. This paper will outline Pure's BWP inspection technology based on two projects in the City of Calgary and include actual results from field verifications of the electromagnetic inspection data.

Colorado Springs, Colorado, has a population of more than 400,000 people with a metropolitan service area of more than 600,000. Colorado Springs Utilities (CSU) had identified a need to evaluate the effectiveness of its current potable water project identification and prioritization model, assess different techniques to ascertain pipe condition and predict pipe failures, and assess alternatives to open cut replacement that would mitigate the risk of water main failure at a lower cost and with reduced impact to customers. This paper provides an overview of studies carried out on the existing program and potable water system in Colorado Springs and the development of a unique risk-based framework to facilitate both condition assessment and rationalization of rehabilitation requirements for its entire potable water distribution network. It also provides both an overview of the overall risk-based approach and examples of initial condition assessment programming tools, techniques, and results. Phase 1 of the program was completed in 2012/2013 and Phase 2, which includes the deployment of field-based condition assessment activities, commenced in 2014.

The primary trunk (PT) sewer was designed to convey wastewater from the Regional Municipality of York and to collect and transport flows from Pickering and Ajax to the Duffin Creek Pollution Control Centre (PCC) in Ontario, Canada. The total collection system area encompasses an area of 47,350 ha (117,004 acre) and a total residential population of more than 1 million people and a daily influx of more than half a million people due to employment in the area. The PT sewer was constructed in multiple contracts in the late 1970s as a low head pressure pipe. While upper reaches of the sewer have been subjected to varying levels of condition assessment, the lower 5 km of pipe (3 miles) has never had its condition formally assessed. The diameter in this area ranges from 2,550 mm (102 in.) to 3,000 mm (120 in.), and the flow regime ranges from open channel flow to surcharged flow with more than 8 m of head. Aside from combined loading, which was practiced in the 1970s, the most significant evolution in structural design of RCP from the late 1970s to present day was the recognition that larger diameter pipes needed to be designed for shear (diagonal and radial) and for flexure and service load crack control. While this concept was introduced by Frank Heger as early as 1963 it was not introduced in any standard practice until the 1993 ASCE standard practice and is still not covered by the present-day ASTM C76 standard. The initial condition assessment consisted of assessing more than 48 unique load cases with finite element analysis (FEA) techniques and additional load cases through parameter sensitivity assessment. Investigations were also carried out to identify all potential deterioration mechanisms for the installed pipe relative to its internal and external exposure environment and prioritize the nature and type of advanced condition assessment tools to be deployed in ongoing assessments. The initial assessment provided a unique overview of the original design of the sewer versus present-day design standards and a summary of the exposure conditions that could affect the rate of degradation of the pipe material utilized in the original construction and established an initial "desktop"condition assessment model to facilitate structural assessment of sewer once more advanced inspections were undertaken. The output of this assessment not only provided the basis for input into an assessment of the surcharge pressures the pipe could reasonably tolerate during long-term operations but also, through examining the vulnerabilities in the present operating condition, established the types of advanced inspection tools that are most advantageous to deploy as the next stage of a condition assessment program.

The benefits of using acoustic fiber optic (AFO) monitoring as a tool for condition assessment for prestressed concrete cylinder pipe (PCCP) is well established in the literature and is commercially available for this purpose. However, the monitoring methods in use today are restricted to documenting the occurrence and location of prestressed wire breaks and making a condition determination based on the sum of wire breaks within a given area. This limits the value of monitoring if the number of wire breaks prior to the introduction of monitoring is unknown. The work reported is the result of field tests designed to improve acoustic signal processing for pipe condition assessment in an experimental environment that included burial, pressurization, and intentional damage to the prestressing wires in three specimens of PCCP. The experimental data was analyzed for average root mean square (RMS) power and peak frequency (HEMP) analysis. While the HEMP analysis did not prove useful, the average RMS power showed promise for correlating the signal amplitude with the number of broken wires.

Important engineering decisions are made every day regarding sanitary sewer, combined sewer, and storm sewer systems, and often involve the use of rainfall data. Although these decisions require significant capital expenditures and are designed to protect life, health, and property, the integrity of rainfall measurements supporting these decisions is often overlooked. The authors have examined guidance from a variety of professional organizations in engineering, water resources, and meteorological fields and have consolidated their findings into a concise, flexible, technically based approach to obtain high-quality rainfall data to support sound engineering evaluations and decisions. The reliability of rainfall data depends on four concurrent factors: selecting suitable rain gauge technologies and products, selecting an appropriate rain gauge density, selecting effective rain gauge locations, and properly maintaining rain gauges once installed. Best management practices in each of these areas are discussed, along with examples of their application within the United States and abroad.

Introduced as a building material in the mid-1900s, asbestos cement pipe makes up approximately 18% of all water mains in North America. Although its use declined in the 1980s after health concerns began to arise, a large amount of asbestos cement water pipe remains in service in many municipalities. While many have chosen to remove all asbestos cement mains from service, the combination of budget constraints and the complexity of its removal means the remaining pipes must be systematically prioritized. Remaining service life calculations based on the physical condition of the pipe are of significant value in this prioritization process. Prediction of pipe failure involves three core components: assessing the main's current physical condition, predicting how the condition will change, and determining the condition in which it will fail. This paper presents a simple yet effective method specific to asbestos cement pipe, with a focus on structural failure of the pipe wall.

Grouts are used in the rehabilitation of various pipelines, particularly for leak control in cracked concrete infrastructures including all types of wastewater and storm water pipelines. Hence there was a need to develop test protocols to evaluate the performance of various types of grouts based on their applications. The aim of the controlled testing program, which was approved by the EPA, was to evaluate the performance of grouting materials used in the rehabilitation of cracked concrete structures, including pipes, to quantify the infiltration using a combination of model and laboratory tests at the Center for Innovative Grouting Materials and Technology (CIGMAT). A combination of grout and grout-substrate bonding with a simulated model test are used to evaluate grouts for leak control at repaired cracks in concrete. Grouts are characterized using working, physical, mechanical, and durability properties. To quantify the grout properties, several ASTM and CIGMAT test methods are used. The concrete crack repairs were simulated using concrete rings placed at selected distance apart. Grouted cracks are tested to 34 kPa (5 psi) water pressure, after subjecting the repaired joints to wet-dry cycles to quantify the effective reduction in water infiltration. Test results of a polyurethane grout was used develop a new parameter to define leakage in the repaired joint. The controlled verification test program approved by the EPA will be of assistance to manufacturers, suppliers, engineers, and owners in evaluating the grouts used for cracked concrete repairs.

Constructing a one-mile-long, large-diameter water supply pipeline through downtown Portland and nearby urban neighborhoods presented a variety of challenges. Extensive coordination, communications, and public relations were necessary throughout the project's duration. The patience of residents, nearby businesses, and the commuting public was taxed repeatedly by long traffic delays and construction noise—both day and night. Besides the many known conflicts that were identified in the design phase, numerous unanticipated surprises were encountered during construction, resulting in lengthy delays and costly change orders. This presentation will focus on the efforts made by the project team—the Portland Water Bureau and contractor—and what was done to overcome the obstacles encountered and construct the project successfully, and the many lessons learned along the way.

The North Texas Municipal Water District (NTMWD) is responsible for supplying raw water to its 13 member cities ultimately benefitting nearly 2 million people. Water from Lake Texoma, located on the Texas-Oklahoma border, accounts for approximately one quarter of NTMWD's supply. Restrictions were placed on pumping water out of the Lake due to an infestation of zebra mussels in 2009 and a major state-wide drought in 2010 and 2011, resulting in NTMWD facing severe shortages to it water supply. In 2011, an initiative was undertaken to have a new large-diameter transmission pipeline built that would bring the zebra mussel-infested water directly from Lake Texoma into a treatment facility in Wylie, Texas. The resulting design was that of a 50-mile transmission pipeline ranging in diameter from 84 in. to 96 in. that needed to meet demands in the summer of 2014. This line had to be built in just over two years, with an aggressive fast-paced design and construction schedule. Failure to successfully meet this schedule-driven project would result in severe impacts to more than a million people. The construction manager at risk (CMAR) delivery method for materials and construction procurement was used, along with other nonconventional methods such as direct communication with multiple pipe procurement during design and release of pipe manufacturer bid packages with only 30% design plans. This paper discusses in detail the means and methods utilized in delivering this large-scale project in the fastest and most efficient manner, design and specification of the pipeline, and pipe material selection from the CMAR engineer's perspective. This is followed by details of the submittal and pipe-making processes from a manufacturer's perspective on three of the five sections of the pipeline.

Open-cut method (trenching) is the conventional method of new pipeline installation underground. Providing embedment materials that meet the design requirements is one of the most important factors that affect total project costs and duration. This research considered a 150-mile pipeline project as a case study to compare five embedment options in terms of cost and production. All calculations were conducted for two types of pipes including steel pipe and prestressed concrete cylinder pipe (PCCP). The embedment options considered were (1) direct reuse, (2) chemical stabilization, (3) CLSM using native soils, (4) import granular material, and (5) indirect reuse. The objective of this research is to identify applicable options for each segment and to compare them in terms of production rate and total costs. Production rate of equipment was calculated using recommended equations for different equipment. It should be noted that the overall production and total costs of each option depended on the type of equipment that the contractor used. Rental Rate Blue Book was used to calculate cost of each option. It was concluded that CLSM using native soils had the highest production rate and lowest total costs for segments with low reusability potential compared with other methods. Also, it was observed that hauling materials from borrow pits had higher total costs than chemical stabilization. However, the production rate of hauling material from borrow pits were higher than chemical stabilization.

In the postconstruction period of horizontal directional drilling, the annular space between the product pipe and the borehole is filled with drilling slurry. As time goes by, the drilling fluid dehydrates and solidifies, which may result in the consolidated annulus involving less moisture and higher strength in the annular space, even some shrinkage gaps. The degree of consolidation of the slurry transforms the stress state of the product pipeline within the annular space and changes the seepage stability of the soil around the pipeline because of its high moisture content and low density. So it is significant and necessary to study the consolidation process of the annular slurry. Two soil-tank experiments filled with clay-sand soil and sand respectively are conducted to study the consolidation process. The strength of the consolidated slurry with different moisture content is also tested through a simple experiment. The soil-tank experiments indicate that when the borehole is stable, the annular space is filled with drilling fluid primarily, accounting for a long consolidation period and higher moisture content and lower strength. Alternatively, when the borehole is unstable, the borehole may slough, crumble, or even collapse, resulting in the mixed consolidated mass with slurry and surrounding soils, accounting for a shorter consolidation period and lower moisture content and higher strength. Shrinkage cracks and several small voids among consolidated bentonite slurry are found both in the two experiments. As a consequence of high moisture and low density and the existence of cracks and voids, the seepage stability of the annulus is reduced.

This paper presents a case study for the development and implementation of quality assurance and quality control measures for the most critical procedures for structural rehabilitation of prestressed concrete cylinder pipes (PCCP) with fiber-reinforced polymer (FRP) composites. The majority of large-diameter water transmission mains nationwide are made of PCCP. Many of the transmission mains have been in service for well over 50 years and are at risk of the failure because of the number of years they have been in service. One of the standard ways to repair PCCP pipelines is to use fiber-reinforced polymers, including glass- (GFRP) and carbon fiber (CFRP) composites. The installation of FRP structural liner inside the pipe includes many operations, such as preparation of the pipe substrate, fiber saturation, etc. Each step of the technological process may compromise the structural integrity of the repair, if performed with deviation from the specifications. One of the most critical procedures for the installation of the internal FRP structural liner is adequate preparation of the substrate (inner core concrete and metal rings) to ensure sufficient bond of the FRP liner material. Nondestructive testing methods are used to confirm the adequacy of the existing inner core concrete strength and to ensure satisfactory concrete preparation to comply with the new standard being developed by AWWA. The strength of the inner core concrete was determined with measurement of the transmission velocity of compression and shear waves. These velocity values are used to determine the elastic deformational characteristics of the concrete and empirically determined strength values. The volume of FRP repairs is constantly growing and quality control procedures for the structural rehabilitation of the PCCP with FRP composites become more critical. This paper and presentation will serve to highlight the most critical issues of the quality control for FRP liners and how to ensure adequacy of the substrate preparation.

The City of Tampa used a streamlined qualifications-based selection for a project management at risk with progressive design build (PDB) delivery of their critical-schedule, high-profile infrastructure projects. CH2MHILL was chosen as the design build program manager to contract for the design and construction of a $250 million water, sewer, and stormwater pipelines and pump station utility capital improvement project, known as UCAP. Forty miles of pipelines were designed and due to the economic downturn and the flexibility of the program contract the program was reduced to $105 million to date for the construction of 20 miles of pipelines and two pump stations. The program offered a single point of responsibility and accountability for all work associated with 25 high-profile individual projects, including eight pipeline projects that were under design and construction simultaneously, 6 miles of downtown business distribution water lines, 5 miles of 42 in. transmission water main in downtown areas, and 5 miles of 42-48 in. force main, two pump stations, and stormwater projects within urban residential and central commercial core of downtown Tampa. The paper will discuss the efficiencies of bringing the community-sensitive, critical-schedule projects into a program that has produced to date a program yielding $3 million in cost-effective construction solutions and $560,000 in sustainability practices. The contract required a transparent, open-book process of cost reimbursable with fee guaranteed maximum price (GMP) and a third-party CPA firm audit. This delivery method resulted in a return of more than $3 million in GMP savings to the City. The early engagement of a public outreach, information, and stakeholder involvement approach reduced public construction complaints by 94% when compared with similar projects in the Tampa area. This paper will discuss the effectiveness of the stakeholder involvement during the design and construction phases of the projects and the satisfaction of owner with the alternative delivery system chosen, which allowed a focused team approach to implement the needed infrastructure projects with the maximum efficiency and minimum amount of disruption to daily activities during construction to residential and commercial stakeholders.

Many utility pipes, especially for water and sewer, have severely deteriorated. While it was estimated that sewer and water pipes will require about $130 billion for repair over the next 10 years, only $42 billion is available. To properly manage the available funds, cities need to come up with conceptual cost estimates that highlight their requirements. Despite the existence of pipeline cost-estimating models that have been developed by those cities, interviews with many city officials revealed that their current cost models might not produce accurate results. This paper presents an artificial intelligence (AI) model that assists cities in the development of more accurate cost estimates for their water and sewer rehabilitation projects. The proposed model was developed using information collected from about 50 projects. Benefits of the presented model include, but are not limited to, better utilization of financial resources, decision-making guidelines, and comparison of alternatives. The presented model also fulfills the needs of funding entities for more accurate cost estimates.

The City of Baton Rouge/Parish of East Baton Rouge (City/Parish), Louisiana, has entered into an EPA Consent Decree. The City/Parish designed and is implementing a sanitary sewer overflow (SSO) abatement program that involves conducting comprehensive rehabilitation and capacity improvements to the collection system. The City/Parish has developed the program delivery plan (PDP), which describes the 107 projects needed to rehabilitate the system and increase its capacity, which involves the replacement of 150 pump stations and nearly 2,000 miles of sewer pipe. One of the more complex projects in the PDP is the Choctaw Storage and Pump Station Facilities project. This project includes construction of one 6 million gallon (MG) aboveground storage tank and one 20 MG aboveground storage tank and three wet weather pump stations to bring the flow to the storage tanks. The project also includes approximately 4.5 miles of force mains between the pump stations and storage tanks, installed using a variety of methods, including horizontal directional drilling (HDD) and jacking and boring. Once overflows from the existing pump stations/trunk lines occur, the overflow pump stations are activated via a master programmable logic controller (PLC). Flow from PS 51A and PS 51AA manifolds into a common force main that goes to the storage tanks. Flow from PS 52A is conveyed from a separate force main to the two storage tanks. At the storage tanks, the flow enters the 6 MG tank first and then the 20 MG tank. When the collection system is ready to receive flow, the pump stations are confirmed to be shut down, and, through a series of control valves, the flow is returned to PS 52 via the PS 52A force main, which then acts as a gravity line. This dual usage allowed the City/Parish to save approximately 2 miles of large piping for the return flow. To be able to start up the entire system, a clean water test was first performed. This brought challenges, because more than 26 MG of clean water was required to fully test the storage tanks and the three remote pump station sites. Once the control system was in place and the clean water test was complete, a 30-day test with wastewater commenced. As part of the startup, the City/Parish requested that piping be put in place at both PS 52A and PS 51A so that the new overflow stations could also pump into the collection system, rather than into the tanks, to perform maintenance on the existing PS 52 and PS 51. This paper will outline the lessons learned during the construction and commissioning of the Choctaw Storage and Pump Station Facilities project, part of the Baton Rouge SSO program.

This paper examines alternative project delivery schemes that have become widely implemented in the infrastructure market. Despite this widespread implementation, the authors present the contrarian view that while in some, if not many, instances alternative project delivery is beneficial, there are circumstances in which traditional project delivery is still the preferred mechanism to bring infrastructure projects to market. Just because something is new, trendy, and even widely used does not make it the best choice for all parties. The need to find creative ways to deliver infrastructure projects to the market has been a catalyst for alternative project delivery. Infrastructure assets are in need of repair or replacement. At the same time owners are financially strapped and struggling to fund the necessary work. These and other factors discussed have fueled delivery schemes such as public-private partnerships (P3s). This paper explores the question presented in part I (whether alternative delivery mechanisms are one size fits all) by introducing the reasons why market participants have turned to alternative project delivery. Part II examines the characteristics of several of these alternatives (e.g., P3s, Design-Build, etc.). Part III discusses factors that must be considered to determine whether alternative project delivery is appropriate. Part IV concludes by arguing that while alternative project delivery can be a tremendous tool, if the project is not an appropriate fit it can be problematic.

Most pipeline designs assume uniform haunch support for the pipe. However, during installation good haunch support is difficult to obtain and to inspect. Research has shown that dumping Class I and Class II soils in beside a pipe creates a void in the lower part of the pipe haunch. Compaction is essential to move the material into this void area and provide the needed uniform support. The current methods of compacting soil into the haunch area are shovel slicing (rodding) or vibration for Class I and Class II soils and mechanical compaction of Class III and Class IV soils. Experiments at the U.S. Bureau of Reclamation demonstrated that the amount of support the haunch provides a pipeline depends on the relative stiffness of both the bedding material under the pipe and the haunch soil. The weight of the pipe, water, and backfill compresses uncompacted bedding so the pipe is effectively supported by the material around the haunch reducing any concentrated load on the bottom of the pipe. Early research by the National Clay Pipe Institute demonstrated the importance of shovel slicing. Recent research confirmed the significance of shovel slicing during installation. In this 2013 work, the relative stiffness of crushed rock placed into pipe haunch areas was measured by both pushing rods and pulling straps at the pipe-soil interface. Significant differences in circumferential support were seen between dumped rock and shovel-sliced rock. In these experiments, shovel slicing increased the support for the pipe about tenfold. For Class I and Class II soils, lifts up to 8 ft thick can be compacted using water and internal vibration. Impact compaction of Class III and Class IV is time consuming, labor intensive, and inherently inconsistent. To achieve a high degree of compaction, the soil should be placed in 6-in. lifts and constantly tested. Because of the difficulty of obtaining uniform haunch support, flowable fill (CLSM or controlled low-strength material) has been used in the haunch areas. For large-diameter pipe (6 ft and greater), flowable fill is the only viable option.

Most trenchless pipeline construction projects are currently delivered using the traditional design-bid-build (DBB) system. DBB is a sequential process that often leads to inefficiencies; therefore, alternative project delivery methods (APDM) have been developed to increase stakeholder integration and ultimately enhance project performance. The complex nature of trenchless construction projects renders them ideal candidates for APDM because of the lack of technical knowledge exchange traditionally seen between the engineers and contractors. APDM can be used to bridge this gap by enabling the contractors to provide knowledge and insights early in the design of trenchless projects, which can introduce numerous benefits over traditional DBB delivery. Numerous APDMs are in use today, including design-build, construction management at risk, and integrated project delivery. APDMs are continuing to gain popularity in the design and construction industries due their documented ability to improve project performance, specifically with respect to project cost and schedule. However, the use of APDM has not yet gained significant popularity in trenchless projects. This paper presents industry perceptions on the potential benefits APDM can offer trenchless construction projects and specifically discusses performance areas that are likely to be affected by the use of APDM.

This paper provides a general overview of the steps JEA has taken to meet future water supply needs in Jacksonville, Florida, while protecting the environment through the total water management plan (TWMP) and highlights the Segment 2 36-in. river crossing design/build project. The river crossing is a key component of the TWMP and one of the longest horizontal directional drills ever completed using 36-in. pipe. The goal of this presentation is to provide utility planners, project managers, and designers with information on the engineering and design/build aspects on this very large and high-profile directional drill. The $80 million dollar TWMP is a capital improvements program to transfer significant amounts of potable water from JEA's North Water Grid to the South Water Grid. It includes six large-diameter pipeline segments. Segment 2, one of the pipeline segments, involved crossing the St. Johns River with a massive horizontal directional drill (HDD) to install more than 6,500 ft of 36-in. steel pipe. The crossing required a full complement of cutting-edge technology and techniques in the HDD field that included the largest horizontal directional drilling equipment available, using the intersect method for the pilot hole with state-of-the-art guidance and survey and utilizing a 300-ton pipe thruster in tandem with a drill rig for pullback. The project also required other trenchless technologies including pipe ramming to install conductor casing at both entry points and auger boring to install a casing for the water main below a major downtown expressway. The 36-in. steel pipe was welded into six intermediate segments along a congested, limited access right of way. Just prior to pullback the segments were maneuvered and welded into one complete pipe string, requiring a heavily coordinated closure of a travel lane and seven ramps along the Arlington Expressway, a major commuter route through downtown Jacksonville. An extensive multiphased maintenance of traffic plan was required. The design/build project required a very compressed schedule and was completed in 10 months, including design, permitting, and construction.

In 2009, China surpassed the United States to become the largest global energy consumer. By 2013, coal, crude oil, and natural gas combined represented more than 90% of this consumption, and it is estimated that China's energy consumption needs will more than double by the year 2040. This projection highlights China's growing challenge to safely and efficiently supply energy resources across the country. This effort will include new supplies to areas with developing rural populations and increased supplies to rapidly growing urban areas. Buried pipeline has become the selected method of transmission, as pipelines are more cost effective, more sustainable, and more efficient than the construction and operation of aboveground railway or long-haul trucking. To meet the demand, the Chinese government has implemented massive buried pipeline construction initiatives, allowing China to become the fastest growing country in trenchless technology construction methods. Horizontal directional drilling (HDD) has played a particularly critical role in executing large-scale pipeline construction by providing an economical, timely, and environmentally responsible method to bypass challenges along the path of the pipelines. Thus, Chinese HDD contractors have played a critical role in the overall development of China's buried energy infrastructure. Understanding this role would be of great value to the global trenchless technology community. Developing countries would benefit from the Chinese advancements for large-scale HDD installation. In developed areas, such as North America, studying Chinese execution may allow for new ideas to help to improve long-established HDD best practices.

Ninemile Point plant was built in the 1950s to accommodate the growing energy demands for a booming New Orleans population. The 550-MW Ninemile Unit 6 CCGT project was proposed to replace the aging units 1 and 2 and provide New Orleans with very clean and efficient electricity generation. To reduce overall project costs, existing infrastructure was utilized wherever possible, including the circulating water system. The project would require some new circulating water lines installed near the building and tie-ins to existing concrete intake and discharge piping. Due to space limitations, certain utilities' corridors could not be relocated to accommodate the new circulating water lines. As a result, it was decided to transition to abovegrade steel pipe to transverse these utility corridors. The new circulating water system was required to be designed for seismic conditions and wind loadings due to hurricanes. In addition, manufacturing and installation schedules were limited as a result of hurricane season. Due to the station's proximity to the Mississippi River, groundwater conditions also had to be considered during design, manufacture, and installation phases of the project. Prestressed concrete cylinder pipe (PCCP) was chosen for below-grade piping (more than 1,500 ft of 72 in.) and steel pipe was utilized (more than 450 ft of 72 in) for abovegrade piping. Materials were delivered on schedule, and the pipe was able to be installed as required to the satisfaction of the design engineer and owner. Consequently, unit 6 will be able to begin operations in mid-2015 and provide long-term and reliable power to the New Orleans area.

Ogden City, Utah, (City) lies between the Great Salt Lake to the west and the Wasatch mountain range to the east. The major source of clean water for the City is Pineview Reservoir, a high mountain lake at the top of Ogden Canyon, which is a narrow gorge that runs from the City to Huntsville, Eden, and the rest of the Uinta-Wasatch-Cache National Forest and the Ogden Valley. There are two waterlines that transport water from treatment near the reservoir at the top of the canyon down to the City for potable use. One of these lines, a 24-in. steel Matheson joint steel pipe waterline, was constructed in the 1910s by pick and shovel. Recently, due to multiple leak repairs, water loss and concern for the integrity of the pipeline, the City could no longer delay the replacement of the pipeline. Replacing the line posed several substantial challenges. The canyon is steep and characterized by hard rock geology. The original alignment was laid generally under what is now Utah State Hwy 39, a windy climb through the narrow gorges and outcroppings of the canyon. Due to the seasonal water demand of the City, the pipeline could only be shut down in the wintertime, which meant that construction would have to deal with inclement weather and the substantial traffic volumes that use the road to reach winter activities in the Wasatch Mountains. Additionally, summer water demand would require that the pipe be brought back online prior to irrigation season in the City. During the project work, the City would be relying solely on the one pipeline to provide potable water demand. Construction began in the fall of 2012 and was completed in the summer of 2013. Along the way, trenchless techniques, mandatory night work, tight project site constraints, traffic issues, temporary water requirements, and schedule all had an equal hand in writing the story of this project and its ultimate completion—all during one of the coldest winters in recent memory. This paper will focus on the construction of the Odgen Canyon Waterline Replacement Project, specifically focusing on the challenges overcome and the unique ways in which they were met.

The Chicago Tunnel and Reservoir Plan (TARP) is a combined sewer overflow system devised in the 1970s to control flooding in the metropolitan Chicago area. The system diverts storm water and sewage through 109 miles (175 km) of large tunnels 9 ft-33 ft (2.7 m-10.1 m) in diameter into holding reservoirs for later treatment and averts sewer overflows causing harmful effects to Lake Michigan. When completed, the TARP system will have a capacity of 17.5 billion gal (66.2 billion L) of storage and will complete one of the largest civil engineering mega projects in the United States. The McCook Reservoir Main Tunnel is a central component to the TARP system as it connects the McCook Reservoir to Chicago's Deep Tunnel system. The finished tunnel comprises a 33 ft (10.1 m) diameter steel liner that bifurcates into two rectangular cross-sectional legs that control the flow of the system through six high-head wheel gates. The tunnel and gates are located at the bottom of a 90 ft (27.4 m) diameter shaft that is 300 ft (91 m) below the surface. This tunnel pipe is one of the largest diameter steel tunnel liners in the country. This paper provides an overview of the project, plus details of the assembly and erection of the steel pipe sections. As these sizable sections could not be fabricated in shippable sized rings, the components to the pipe sections and bifurcations were required to be fabricated in more manageable piece sizes. An initial task for the construction team was to maximize the sizes that would minimize the onsite assembly requirements. In addition, the weight of some subassembled pieces was in excess of 180 tons, and most pieces required rotational manipulation during installation. An added challenge was to perform this subassembly, fitting and welding of high-strength steel in Chicago during winter conditions.

Pipe ramming is an emerging trenchless technique that allows installation of pipes and culverts in soils that can pose difficulty to other trenchless technologies. However, because pipe ramming hammers provide high-frequency impact blows to the pipe, high-magnitude stress waves travel down the pipe and are transmitted to the surrounding soil. This can have a serious adverse effect on adjacent structures and nearby utilities if located sufficiently close to the pipe alignment. The potential effects include differential settlements, densification, and local liquefaction depending on the soil and groundwater conditions. Owing to the lack of field observations in the literature, this study was conducted to observe the ground vibrations that can result from pipe ramming and to provide guidelines for the prediction of pipe ramming-induced vibration. An experimental pipe-ramming project was conducted that consisted of the installation of open-ended steel pipe 1,070 mm in diameter and 36.5 m long rammed with two pneumatic hammers. Observations indicated that the vibrations measured at the ground surface largely comprised surface waves, and that vibrations propagate most intensely from the face of the pipe, but also from the surface area of the embedded casing. Ground vibrations are presented as a function of frequency content, magnitude of peak particle velocity, proximity to the source, and direction of propagation. The information obtained from the experimental evaluation of pipe ramming-induced ground vibrations reported herein can provide the means for a first approximation of vibration-induced damage susceptibility.

Lake Travis is located northwest of the City of Austin, Texas. Due to the unanticipated population growth in the area, Austin Water Plant No. 4 was designed and constructed in the "hill country" to extract water from the lake. The raw water line is located between the raw water pump station and the water treatment plant-raw water flume. This part of the project consisted of approximately 3,900 linear ft of 84-in. steel water pipe installed in a tunnel. The installation contractor had concerns that its crews would have fit-up problems with butt-welded field joints due to numerous horizontal curves so the contractor requested alternative solutions. Consequently, the pipe manufacturer and installation contractor worked in cooperation to devise an appropriate jointing system that fit the intended application. The joint was unique in that it allowed for lap welding to be utilized for deep insertion, which in turn permitted greater flexibility for installation of the steel liner pipe into the tunnel. The objectives of this paper will be three-fold: (1) to describe the art and engineering of jointing steel pipe (the process of welding steel pipe joints, the differences between butt welding and lap welding, beveled joints, etc), (2) to discuss the design and subsequent redesign of the field joints on this project, and (3) to discuss the installation process. The paper will discuss these items from both a manufacturer's and an installer's perspective and will describe the background of what led up to the final design and manufacture of the field joint supplied. Changes that took place between the design and approval process and the final installation will also be explained in detail. The contents of the paper will be useful to owners of large-diameter water transmission systems, design engineers, and the construction community.

This paper describes two horizontal directionally drilled water main crossings beneath the Biscayne Bay to support the $31 million emergency replacement of the access bridges to Key Biscayne. The Miami-Dade Water and Sewer Department (MDWASD) replaced two sections of the existing 12-in. (300 mm) ductile iron water main between the City of Miami and the Village of Key Biscayne with 16-in. (400 mm) inner diameter high-density polyethylene (HDPE) pipe via horizontal directional drilling (HDD). HDD technology enabled the installation of the pipelines to be completed within the tight 10-month project schedule, minimizing environmental impacts and project costs. The installations were completed as part of the design-build replacement of the Bear Cut and West Bridge superstructures by Kiewit Infrastructure South Co. The existing water main was supported on the superstructure of the bridges, which forced its fast-tracked replacement. This is one of the most critical projects being completed in Miami-Dade County and will provide a new water main and improved access to more than 10,000 residents in Key Biscayne.

Being a design engineer and project manager of more than 100 miles of large-diameter pipeline projects (greater than 36-in. diameter) and installation has led to the privilege of witnessing multiple contractors and different installation techniques of pipe joint protection sleeves. This also has led to the experience of seeing corrosion problems on polyurethane-coated steel pipelines at pipe joints that can many times be related to poorly installed joint protection shrink sleeves. It has also exposed how the installation techniques and knowledge varies from contractor to contractor and even from work crew to work crew. A growing experience and understanding led to the realization that the heat-shrink sleeves were an important key to protecting one of the most vulnerable areas of the pipe during the installation process, which also led to the need to try and provide owners with quality installation of these products. In gasketed and weld-after-backfill installation techniques, the heat-shrink sleeves provide a very important protection layer to the steel pipe at these crucial points along the pipeline. A majority of the leaks and failures on pipelines are at the joints no matter what material the pipeline happens to be, so the need to find a way to ensure a better quality installation of the heat-shrink sleeves on polyurethane-coated steel pipes became apparent. Therefore, after witnessing several projects where a field representative of the heat-shrink sleeve manufacturer came out on site and performed field testing and installation instruction with the contractor crew members, the need was apparent for design engineers and resident representatives to conduct testing on heat-shrink sleeves. This would provide the opportunity to catch errors or improper installation techniques early on in the pipeline construction to try and minimize future corrosion problems that could potentially cause leaks or damage on the line. This testing started being performed at the very beginning of pipeline installation to verify the sleeves are properly installed and performing as they are intended for the protection of the pipeline joints. Data and information will be presented on how and when to perform the testing, what to look for, how to follow up with the contractor's crew, and how to convey testing results with the manufacturer's representative if necessary. Addressing this testing in the specifications of each project will also be addressed. These tests have been very valuable and have positively corrected poorly installed heat-shrink sleeves on pipeline projects. These tests are simple, but very effective and when performed early in the construction process, can help protect multiple areas of vulnerability along many miles of large-diameter pipelines.

In the late 1970s, the City of San José converted the former Alviso Sewer Treatment Plant into a transmission pump station, known as Spreckles Pump Station, conveying approximately 1 MGD of wastewater from Alviso through 6,900 linear ft of a 10-in. AC force main to the regional wastewater facility. Since the 1970s, no significant improvements were performed to the mechanical and electrical systems at the Spreckles Pump Station. Concurrently, the 10-in. AC force main had experienced pipe ruptures due to the age and pipe material type. Due to its close proximity to an environmentally sensitive habitat, the City initiated a project to upgrade the pump station and install a supplemental force main. The paper evaluates multiple design and construction methodologies for the force main based on site-specific conditions. Also, the implementation of an alternate bid approach for trenchless technologies helped control construction costs and reduced permit requirements and project schedule by 1-2 years. A performance-based approach was utilized to help select qualified trenchless contractors during the bidding process. Other project challenges included potential presence of asbestos; pipe material, special trench details; design of access manholes; value engineering of trenchless shafts; and construction sequencing to maintain sanitary service during construction.

Construction of the Mill Woods Double Barrel commenced in 2009 and is expected to be completed by 2015. The total cost is expected to be $56 million. This project encountered several design, political, and geotechnical challenges, each of which demanded a quick but precise response from the project team. The design factor corresponds to the project team's mandate to evaluate the best way of excavating the tunnels by utilizing the existing equipment available to the City of Edmonton. The political factor emerged during the project team's decision-making process of determining which section of the project should be constructed first and put in service. The geotechnical factor led to the team needing to revise the tunnel alignment and change the tunnel-boring machine to accommodate the change to the tunnel. This paper will describe each of these factors and the required changes in detail and detail the procedure that the project team followed to arrive at its decisions.

The Southwest Metropolitan Water and Sanitation District (District) provides water distribution and sanitary sewer collection and transmission service to approximately 35,000 customers in the Denver Metropolitan area. The District's sanitary sewer collection system includes approximately 18 miles of reinforced concrete pipe (RCP) interceptor sewers ranging in diameter from 15 in. to 60 in. Most of the interceptors were constructed between 1963 and 1969. In 2011, the District identified several reaches of interceptor with severe deterioration due to hydrogen sulfide and sulfuric acid attack. The decision was made to rehabilitate the District's interceptors with cured-in-place pipe (CIPP) methodology. The District developed a plan to rehabilitate all of their concrete interceptors over a period of five years. The D-Line and A-Line projects were designed and constructed in 2012 and 2013, respectively. Collectively, the two projects included installation of more than 27,000 llinear ft of CIPP ranging from 33 in. to 60 in. in diameter, rehabilitation of 95 manholes and vaults, and bypassing flows of up to 13.7 MGD. The D-Line was completed in 2012 for $2.3 million. The A-Line was completed in early 2014 for $3.5 million. The projects included work inside the right of way of two state highways and required coordination with the Colorado Department of Transportation, U.S. Army Corps of Engineers, local parks and recreation departments, city and county officials, and several private residents and businesses. This paper discusses construction challenges encountered in the progress of the D-Line and A-Line projects, including bypass installation, testing of manhole lining products, repairing a fiberglass flume damaged during CIPP installation, and addressing failures of CIPP and manhole-lining products. Construction of the C-Line project will be completed in summer of 2014. The C-Line will include rehabilitation of approximately 8,100 linear ft of 15-in. to 36-in. sewer and 40 manholes. Two other phases are anticipated to follow the C-Line, with complete rehabilitation of all of the District's concrete interceptors anticipated by 2016.

Pipeline owners have completed many in-situ repairs of large-diameter PCCP over the past several years utilizing fiber-reinforced polymer composites (FRP). FRP is one of the most successful trenchless repair methods for full structural upgrade to specific pipe sections. During the design and field activities, owners, engineers, and contractors at times encounter and have to work together to overcome challenges. One such problem is when the existing concrete substrate is not compliant with proposed standard requirements. Through owner-engineer-contractor collaboration, design and construction solutions to resolve poor substrate conditions have been developed. In addition, innovative techniques for surface preparation of concrete and metallic substrates have resulted from tackling and overcoming these conditions. By sharing this knowledge and these concepts, the growing industry standard for FRP upgrades and repairs will be improved. This paper will provide up-to-date information on construction best practices, along with input on how to address substrate deficiencies.

As oil and gas production move into deeper water, the network of pipelines needed for the operation represents an increasingly significant part of the facility cost. The risers and pipelines laid on very soft seabed soils partially penetrate into the soil based on the method of placement, submerged self-weight of the pipelines, and shear strength of the soil. Based on the type of insulation used, steel or plastic outer surface will come into contact with the soil. Hence in this study, plastic pipes representing insulator-coated pipes, with outer diameter of 63 mm (2.5 in.) and 88 mm (3.75 in.) were tested in a somewhat large soil box containing very soft soils. The shear strengths of the soils used in this study were 0.3 kPa and 1.1 kPa. Several mathematical models have been developed to predict the pipe penetration into the soil without taking the loading rate into account, which is considered to be a major limitation of these analytical models. Movement of the pipes also results in the formation of soil berms in the vicinity of the pipes, which will restrict future pipe movements. Hence a need exists to better quantify the soil resistance during vertical pipe movements at various loading rates with the formation of soil berms. In this study, two analytical models have been developed to verify the physical model tests. The laboratory model tests were focused on better quantifying the relationship between pipe penetration resistance with the rate and the soil properties. The new analytical models predicted the vertical force-pipe penetration relationship very well by taking into account the rate and depth of penetration.

In today's urban environment, rights of way are becoming crowded with utilities. Existing utilities in any rights of way have the potential to affect construction. With a deliberate, thoughtful approach to establishing the location of existing utilities, understanding the risks associated with each existing utility, and developing a risk mitigation strategy for each utility during construction, costly impacts can be minimized. This paper presents information on the potential availability of utility information and potential inaccuracy of the associated information. With the understanding by the engineer that survey base maps may show locations of utilities inaccurately, project risks can be identified by understanding potential failure modes for utilities. With risks identified, risk mitigation strategies can be developed. This paper also provides examples of how utility mitigation was implemented on King County, Washington's North Beach Combined Sewer Overflow Reduction project.

The Southwest Pipeline Project (SWPP) in southwestern North Dakota is a large state-owned regional water system providing water to 32 communities and more than 5,000 rural water users through a network of more than 4,200 miles of main transmission and distribution pipelines and pump stations. The project supplies raw water to the 3.5 MGD Oliver-Mercer-North Dunn (OMND) Water Treatment Plant (WTP) located 11 miles from the source and the 12 MGD Dickinson WTP located 87 miles from the source. System improvements to increase the project capacity were identified in a 2008 report. A key component of those improvements is the supplementary raw water intake. The ND State Water Commission (SWC) authorized Bartlett & West/AECOM to perform the tasks necessary to complete final design and preparation of bid-ready documents for a secondary raw water intake for the Southwest Pipeline Project. The secondary intake will provide additional capacity above the capacity of the existing raw water intake facility. The supplementary intake facilities will consist of a 154.5 ft. deep vertical caisson underneath a pump station. An intake pipeline will be constructed to connect the caisson with the screened intake structure located approximately 2,700 ft away on the bottom of Lake Sakakawea's Renner Bay. The pump station and caisson will be located approximately 500 ft west of the existing SWPP Intake Booster Pump Station and the Basin Electric Power Cooperative (BEPC) Intake Pump Station. The new supplementary intake will be connected to the existing 30-in. diameter steel SWPP raw water transmission pipeline on property owned by the U. S. Army Corps of Engineers (COE). Construction of the intake pipe was proposed to be accomplished using the horizontal directional drilling (HDD) method. The bore pit would have been located on private property to the southwest of the pump station. The HDD would intersect the caisson and the intake pipe, made of either fusion-bonded epoxy-lined and coated steel pipe, or high-density polyethylene (HDPE) pipe, would be pulled back to the caisson from the lake insertion point. The project was advertized for bids in July of 2013 and three bids were received from the prequalified list of five contractors. In a surprise to the design engineers, the selected contractor has proposed to construct a much larger-diameter caisson and use microtunneling to install a much larger-diameter intake pipe. This paper describes the project to date.

This paper describes methods for calculating the maximum diameter of grit particles that could be transported through a force main with adverse (e.g., steep to vertical) slopes by varying the slope, diameter, and thus the associated velocity that can be achieved in the force main. These analysis methods are derived from sediment transport theory and do not rely on the rule-of-thumb velocity criteria or empirical observations that are typically used to estimate grit transport in force mains. The approach is generalized such that particle characteristics (sphericity, density) and fluid characteristics (viscosity, density, fine sediment concentration) can be specified. To demonstrate application of the proposed methods, the results of a grit transport hydraulic analysis are presented for a segment of an approximately 4.6 mile long, up to 64-in. diameter CSO force main with adverse slopes that will convey a maximum of 110 MGD of wastewater. This paper also discusses design features that encourage the transport of grit particles through force mains and minimize deposition.

This paper discusses tips and tools to assist with the design of ductile iron and polyvinyl chloride (PVC) pressure pipelines including a summary of reference materials useful to designers; a discussion on available sizes, pressure classes, and joint types; a discussion of software tools and their use; and several design considerations related to topics on pipe fittings, installing pipe on curves, thrust block designs, installing pipe inside of casings, backfilling the trench, and hydrostatic pressure testing. The topics presented should benefit the water conveyance community by providing useful information to engineers, designers, and constructors of ductile iron and PVC pipe systems. Some of the basic information should be of help to staff who are unfamiliar with ductile iron and PVC pipelines, while other information should help sharpen the skills of experienced designers.

Buried pipelines can be damaged by permanent ground displacement (PGD) resulting from faulting, landslides, liquefaction, etc. The mitigation of PGD below grade is an important area of research. Recent research has explored how expanded polystyrene (EPS) geofoam can be used in trench systems to reduce the deleterious effects of PGD moving a pipe laterally beneath ground surface. This paper shows how EPS geofoam can be used in trenches as a compressible inclusion to reduce potential pipeline damage from lateral pipe movement. As part of the testing methodology, a pipe was moved into an EPS geofoam and sand backfill surrounding the pipe to measure the nonlinear interaction between EPS geofoam and the pipe and to develop the soil-EPS nonlinear springs required for pipeline design. The relationships obtained from EPS-soil system were compared with the soil-structure interaction springs from common backfill. The research team found that the EPS-soil system significantly reduces pipeline stress for the case where the pipeline undergoes horizontal offset when placed correctly for maximum benefit.

Pipeline installation in sandy and saturated soils requires special considerations by designers and contractors. The constrained modulus (Ms) of soils has been used to aid the design to predict deflection and buckling of buried pipe. Geotechnical investigation data collected along a 240-km (150-mile) pipeline alignment were used to calculate modulus values within trench zone depths of 2.5 to 6 m (8 to 20 ft). Field and laboratory data were evaluated for two soil types: loose and dense sands. Traditional textbook values of E'n, modulus of soil reaction of the native soil, were derived from field and laboratory methods. Constrained modulus, Ms, values were derived from cone penetrometer tests (CPTs). The purpose of the study was to develop a reliable method of using the CPT for evaluation of constrained moduli in comparison with field and laboratory data derived E'n. When compared with the textbook values of E'n from field and laboratory data in the pipeline industry, CPT technology is a value-added and effective tool for use as a diagnostic indicator of constrained modulus, Ms. Continued and more extensive use of CPT technology may lead to CPTs as a primary tool in determining saturated sand conditions for estimation of pipe deflection in the pipe trench zone for engineering design.

The geotechnical investigation and evaluation should include a balance of methods to acquire and evaluate subsurface information, including drilling and sampling, laboratory testing, geophysical surveys, cone penetration testing, and pressuremeter testing. The geotechnical approach should satisfy the design input requirements for the applicable pipe design standard. This paper focuses upon buried flexible pipe presented in standards such as AWWA, American Lifeline Alliance, and Steel Tank Institute. Methods of geotechnical evaluation may range from determining E' from a lookup table to evaluation of soil moduli such as constrained modulus by laboratory or in situ testing methods. Correlations may be made using soil moduli with overburden pressure and other soil parameters, however, the reliability of the results must be assessed for reasonableness based on project experience. The pipe design team for the geotechnical phase should include geotechnical engineers, engineering geologists, and pipeline designers working together to define appropriate design input parameters for the soils along the pipeline. Geotechnical engineers use standard procedures to investigate and evaluate soil parameters with data collected from boring locations that may range from 1,000 to 5,000 ft centers, as deemed appropriate for the soil types and geologic variability along the pipeline. Engineering geologists evaluate the soil strata between boring locations and assess the dimensional representation of geotechnical soil conditions.

The San Antonio Water System (SAWS) serves more than 1.6 million people and more than 465,000 water customers in the greater San Antonio area and surrounding counties. Over the last several decades San Antonio has experienced rapid population growth, the integration of the Bexar Metropolitan Water District, regulatory withdrawal limitations, and increasing drought restrictions that have put a strain on the Edwards Aquifer, San Antonio's primary water supply. SAWS has been working to meet the increased water demand through a strategy of conservation, reuse, and investments in new water supply resources. The Regional Carrizo Program (RCP) is a water supply project that was developed through a cooperative regional partnership with the Gonzales County Underground Water Conservation District, the Schertz-Seguin Local Government Corporation (SSLGC), and the Gonzales County Water Supply Corporation. Through this unique partnership, the project will convey up to 12,688 acre-ft of Carrizo Aquifer groundwater to Bexar County, which represents the largest non-Edwards water supply in SAWS' history. This paper will focus on the planning, design, and construction for one of the most challenging components of the RCP: fast-track design and construction of the 11.5 mile, 36-in. diameter water delivery pipeline (WDP). The WDP will transmit water beginning in the City of Schertz and traverse through three counties and four cities, terminating at an existing SAWS pump station on the northeast side of San Antonio. Challenges faced during the planning phase included route selection through urban residential and industrial areas, future road expansions, drainage channels, new land developments, and numerous utilities. Unique design elements included provisions for construction of a pipeline within drainage channels; acquisition of easements from more than 60 landowners; and multilevel coordination with counties, cities, state agencies, and utility owners. Construction challenges included urban construction, extensive bore/tunnel crossings, two interstate highway crossings, railroad crossing, unforeseen utility conflicts, new development, a major creek crossing, expedited submittal reviews, coordination of pipeline tie-ins and testing, interior inspection of 11.5 miles of 36-in. steel pipeline, and oversight of multiple installation crews to meet the program schedule.

The general design guidelines for steel pipe are given in AWWA Manual M11. The objective of this paper is to recommend a few special design considerations for steel pipe. These conditions are the diameter limitation for bell and spigot gasketed joints, steel selection for seismic considerations, additional measures for low stiffness in situ soils in the pipeline alignment, and required improved toughness properties for pumped mains with large daily pressure fluctuations. Gasketed joints for steel pipe have been used commonly up to 60 in. in diameter under normal operating conditions; larger diameters with special provisions have also been used. The diameter limit depends on many factors, which include maximum internal pressures, pipe stiffness, joint type and tolerances, backfill and in situ soil stiffnesses, and allowable pipe deflections. The performance of the rubber gasketed joints for three southern California pipeline projects with diameters of 89 in., 96 in., and 132 in. will be reviewed along with their original design criteria, so that recommendations can be made. The physical properties of coil or plate steel are critical for the design of steel pipelines subjected to seismic strains caused by movement of nearby faults or anticipated large surface deformations at fault crossings. The strain-based design for such events includes special metallurgical requirements for ductile steel with low yield strength. The metallurgical requirements for the special steel used on two projects will be presented. Backfill and in situ soil stiffnesses are critical for the long-term performance of the buried flexible pipelines. When the in situ soils have poor load-bearing characteristics and their stiffness is less than the required stiffness of the backfill soil, additional design provisions such as the use of soil-cement backfill, increase of the trench width, and evaluation of the combined effect of the backfill and in situ soils should be considered. These recommendations will be discussed, and a test program that includes evaluating soil cement backfill in poor in situ soil will be presented. Steel and weldment material with improved toughness properties are required to avoid long-term fatigue failure on pipelines with large daily cyclical large pressure fluctuations and flow reversal. A discussion on this topic will be presented.

The new South Platte Interceptor (SPI) project for the Metro Wastewater Reclamation District (the District) in Denver, Colorado, required design of multiple tunneled crossings with pipe diameters ranging from 30 in. to 78 in. and tunnel lengths ranging from 190 ft up to 3,700 ft. The District's goals for the overall project, including the tunnel work, were threefold: (1) Design robust infrastructure that will require minimal maintenance. (2) Promote optimal pricing from qualified contractors. (3) Manage the District's exposure to risk from construction claims and environmental upsets. Using these goals as a charter, the project team consisting of the District staff, seasoned pipeline designers, permitting specialists, and expert tunnel engineers collaborated to prepare design documents for the project. In addition to variations in diameter and length, the geology of each tunneled crossing also varied greatly from dry claystone bedrock to sands and cobbles below the water table. Tunnels were required at major roadways, the South Platte River, irrigation canals, and a golf course. Early on, the project team concluded that tunneling technologies that were technically appropriate for one tunnel definitely were not appropriate for other tunnels. To meet all of the District's goals, the team used a menu approach for tunnel design. With this approach, the design documents describe all of the challenges and operational requirements unique to each tunneled crossing and provide a menu of tunnel technologies from which the contractor may choose to construct the tunnel. This paper will describe the process used to select acceptable tunneling technologies for each crossing and steps taken to have only experienced and qualified contractors bid on the work.

Pipeline systems with two or more centrifugal pumps running in parallel with check valves at their discharges are exposed to the occurrence of check valve "slam" and its undesired consequences. At early phases of engineering, detailed information about the system is typically unavailable and there are also limited resources (job hours and short schedule) to carry out an adequate assessment of the "slam" phenomenon. A good understanding of this problem requires running a number of advanced hydraulic transient simulations, which is a time-consuming activity. Therefore, it happens that the problem is simply disregarded or, in the best case, a conservative selection of check valve type is made. The result is that eventually the choice could be underestimating or overestimating the real needs of the system, with the corresponding impact in costs. Besides, it could happen that in further engineering phases the choice made before could be considered definitive and no additional analyses are carried out, leading to real problems later during operations. This work offers a simplified and practical criterion to help engineers in selecting adequate types of check valves during early phases of engineering, so they can indirectly address the check valve slam phenomenon and simultaneously be able to present a more realistic cost estimation of these items.

Box jacking (BJ) is a trenchless method to install reinforced concrete boxes underground. Over excavation (overcut) is required during box installation to reduce friction force between box segments and surrounding soils. Surrounding soils may collapse during project execution or after project completion and cause surface disturbances and potentially damage road embankment. The main objective of this paper is to develop a statistical model to estimate maximum surface settlement associated with box jacking using eight factors including 1) soil modulus of elasticity (E), 2) soil friction angle (φ), 3) soil unit weight (γ), 4) soil cohesion (c), 5) box culvert height (h), 6) box culvert width (w), 7) overcut size (s), and 8) depth of box culvert from the surface (H). PLAXIS 2D, a finite element modeling software, was used to generate box jacking models under different site and project conditions. In total, 300 box jacking models were generated and corresponding maximum surface settlements were recorded. Then, multiple linear regression (MLR) analysis was conducted to investigate the relation between considered factors and maximum surface settlement. The minimum depth of box from the surface (H) was assumed to be at least 2h. Therefore, the suggested MLR model is not applicable for box culverts installed in depth less than 2h. It was concluded that the soil cohesion (c) was the most significant factor in determining maximum surface settlement. Results showed that soil friction angle (φ) did not have any correlation with maximum surface settlement.

The Proceedings of the Thirty-Seventh Annual Meeting of the Highway Research Board, Washington, D.C., January 6-10, 1958, included an important milestone in the history of underground pipe design: the birth of the Iowa formula for flexible pipe deflection including the modulus of soil reaction, E', at the hands of the late Professor M. G. Spangler and Emeritus Professor R. K. Watkins. Little did they know that their vision would turn into widespread confusion leading to a plethora of opinions, methodologies, and charts and graphs among various segments of the pipe industry and the design engineers. For nearly six decades, the "body of knowledge" has been flooded with hundreds of manuscripts on E'. In spite of the deluge of published "solutions," there has been no unified agreement among authors, pipe manufacturers, design engineers, specification writers, standard writing bodies, utilities, and regulatory agencies. Writers have debated about a) what factors of the pipe-soil system govern the choice of E'; b) whether E', which is not a fundamental soil property that is measured either in a laboratory or in situ, can be replaced with constrained soil modulus, Ms, which is measured in a laboratory procedure; c) how native soils have an impact; d) what role does the fundamental geotechnical principle that effective confining pressure has the most influence on the soil modulus play in translating this phenomenon to the depth of soil controlling the value of E'; e) to what extent the relative stiffness ratio of the pipe to the bedding controls E'; f) are we calculating the horizontal or vertical deflection; g) do we use prism load or Marston's load; h) do we need a shallow cover correction factor; and many other questions. Most of the "solutions" result in, at best, a "feel good" attitude on the part of the design engineer. The bottom line is that all the fancy academic exercises, models, finite element analyses, MathCAD engines, excel workbooks, equations, and graphs are not useful if the final shape of the installed pipe is not measured before acceptance; serious problems surface; and we meet in court. In the final analysis, the three most important factors are the pipe soil stiffness ratio, the pipe shape control, and the neglected orphan on the job—inspection. This paper presents a historical overview of the lessons not yet learned by pipeline engineers and makes a strong case for modern tools such as laser profiling.

Steel pipe has long been designed for internal pressure with varying safety factors applied to the allowable design stress in the steel cylinder. Earth loads on rigid pipe were first developed in 1913 by Anson Marston and then modified by Marston and Merlin Spangler in the early 1930s for flexible pipe. However, checking steel water pipes for resistance to external loads was not common until the early 1960s after Reynold Watkins corrected the original Iowa Formula (by Spangler) and the Modified Iowa Formula was published in 1958. This paper will discuss the use of the Modified Iowa Formula that is still utilized by many design engineers along with subsequent work that has been developed over the past 50 years and published. This subsequent work is based on measurable soil parameters that will be presented and discussed along with steel water pipe serviceability levels against external loads.

ASTM F 1962, Standard Guide for Use of Maxi-Horizontal Directional Drilling for Placement of Polyethylene Pipe or Conduit Under Obstacles, Including River Crossings, provides a convenient procedure for estimating installation loads and stresses on polyethylene (PE) pipe as primarily a function of the drilled path and buoyant weight of the pipe in the borehole. The ASTM theoretical model does not consider the impact of pipe bending stiffness on the associated tensile loads during maxi-horizontal directional drilling (maxi-HDD) installations, because it assumes that such effects may be ignored for flexible PE pipe material. In contrast, the method adopted by the Pipelines Research Council International (PRCI) was developed for application to steel pipe and explicitly considers its somewhat high bending stiffness. There are also other differences in the two techniques, including the approach for estimating the effect of fluidic drag as the pipe is pulled through the viscous drilling fluid and consideration of the effect of tension at route bends. Both methods, or modified versions, have been applied to pipes of various materials. The present paper discusses the basic differences between the ASTM and PRCI methods and the implications of their application to pipe materials other than those originally intended. In principle, either method may be applied to PE, steel, or other type pipe, but the degree of design margin, or effective safety factor, may be significantly different, depending on the method and installation details. In particular, the PRCI method tends to be more conservative due to its somewhat high estimate of the fluidic drag contribution. This may be most significant for HDD installations with low frictional loads within the borehole due to relatively low buoyant weight, such as may occur for heavy (e.g., thick-walled steel) pipe, or where internal ballast is employed to reduce the otherwise high buoyant weight of the pipe.

The Tarrant Regional Water District (TRWD) and the City of Dallas Water Utilities (DWU) are designing a raw water conveyance system with a capacity of 347 millions of gallons per day (mgd). The proposed system consists of an approximately 150-mile long integrated pipeline (IPL), three lake-intake pump stations, and three booster pump stations. The program management team performed a hydraulic transient analysis for the IPL and the pump stations to (1) determine if there are unacceptable pressures in the pipeline during normal and emergency operating conditions; (2) develop a surge control strategy, if necessary, to mitigate adverse hydraulic conditions; and (3) determine a safe opening time for the discharge control valves during pump startup. The key challenge for these analyses was to avoid full vacuum during a transient event as the full vacuum condition may create column separation in the system that can generate excessive positive pressures due to the rejoining of separated water columns. Transient analysis software HAMMERTM V8i (HAMMER) by Bentley Systems Inc. was used for this study. The model considered air valves at the critical locations along the pipelines and around the pump stations to control negative pressures in the system. This paper presents the analysis and the results for selecting the surge control devices to keep system pressures within allowable limits during normal and emergency operating conditions.

The T-Bar Ranch Well Field Development and Delivery Project involved the design and construction of 44 water production wells and associated collection piping; a 75.7 ML/day (20 MGD) high-service pumping station; two ground storage tanks (one 7.6 ML [2 MG] and one 18.9 ML [5 MG]); a chlorination facility; and 93 km (58 mi) of 122 cm (48 in.) diameter transmission main, all in a time span of less than 15 months. The fast-track design-build delivery project commenced in March 2012. Many hurdles had to be overcome, including establishing a pipeline route that traversed around sand dunes and through a wind farm and crossed multiple oil/gas lines; performing property surveys and preparing easement documents and swiftly securing easements; performing an expedited yet thorough system hydraulic analysis; performing geotechnical investigation and topographic survey; implementing a phased pipeline design approach that involved the early procurement of pipe and valves; and mobilizing multiple pipeline construction teams and equipment, which included some of the largest trenching machines ever utilized. Due to the sustained drought in west Texas, and extremely low reservoir levels within the region, the project was required to be online by June 2013 to ensure the City of Midland would have adequate water supply during its peak summer demand. Design-build was selected as the project delivery method due to the aggressive schedule requirements.

The purpose of this paper is to present a case history of the Interstate 84 and U.S. Highway 6 Directional Microtunnel (I-84 DMT) crossing located near Matamoras, Pennsylvania ,and look at this innovative project as a whole to learn how the methods can be applied to future trenchless crossings with difficult site conditions. The crossing was a critical part of the Tennessee Gas Pipeline Company, LLC (Tennessee Gas), a Kinder Morgan Company, Northeast Upgrade Project (NEUP). Due to environmental and cultural resource areas and other constraints, the crossing had to be made where it was located despite challenging trenchless and geotechnical engineering issues posed by the location. Due to geometric and geotechnical constraints several trenchless crossing methods were considered before the design team ultimately selected curved or directional microtunneling. The crossing was completed using Herrenknecht AG's (Herrenknecht's) Direct Pipe (DP) tunneling system incorporating Permalok casing pipe in a segmental or cartridge fashion because not enough workspace was available for a conventional DP pipe string layout. The 470-ft-long crossing consisted of 42-in.-diameter casing pipe in which the concrete-coated, 30-in.-diameter high pressure steel gas pipeline was later installed.

Over the past 20 years there has been much research and verification as to how buried pipes interact with the surrounding soil(s) (soil-structure interaction theory) and also how this relationship is evolving over time. Concurrent with this body of study, other engineering academicians have also developed an understanding of how the addition of a flexible liner into this existing soil-structure interaction system will perform after the liner's installation. This paper introduces to the practicing engineer the work currently underway by a task group of the PINS committee charged with producing an ASCE Manual of Practice (MOP) for flexible liners in host pipes that are designed for gravity applications such as culverts, storm sewers, and wastewater collection and transportation systems. This task group, in conjunction with others working around the world, is seeking to take this vast body of engineering knowledge and consolidate it into a practical and usable form for the practicing engineer. In keeping with the professional engineer's need to properly document the design process he or she is employing, the new MOP is currently envisioned to cover not only the design process itself, but also the engineering assessment of the existing pipe-soil conditions that must precede the design process so that assumptions made will reflect the true needs of the renewal process. This knowledge of the state of the stresses in the existing soil-structure interaction system is a prerequisite to qualifying the liner for the typically desired service life of 50 years or more. This proposed design methodology considers the impact of both the global and the local imperfections present in the existing pipe and/or liner system. The new methodology can handle noncircular standard and nonstandard pipe shapes in addition to just the circular-shaped pipes addressed by the nonmandatory design appendix of ASTM F1216, which has, by lack of a more formal design standard, become the default design methodology for most practicing engineers in North America. Written in 1985 essentially for the pipe size range 8 in. to 12 in., its extension into the larger size pipes has led to inefficient wall thicknesses in these larger sizes that are hard to install well and lack the compliance with the shape of the host pipe structure desired by engineers and owners.

Water and wastewater pipe product standards, e.g., those developed by AWWA or ASTM, are commonly cited in project specifications and largely relied upon in project design. Different pipe materials have different standards, and many materials have more than one pipe standard. These pipe standards outline the minimum requirements, but do not contain all of the engineering and administrative information normally contained in specifications. In addition to standard dimensions and minimum QA/QC testing requirements, most pressure pipe standards include pressure class (PC) or pressure rating (PR) designations that provide for some margin of safety. This paper reviews the standards for several commonly specified water/wastewater pipe products with regard to their methodology for arriving at the recommended pressure class designations. Both similarities and differences in the methodologies employed are explained. Their impact with regard to various pipe applications is also evaluated. This review includes recent proposals that advocate a less conservative approach to assigning pressure class for some water and pressurized wastewater pipe products. The effects that different pressure classification approaches have on in-service performance, reliability, longevity, and sustainability are discussed. Pressure pipe design factors should not be raised, or safety factors reduced, until in-service or simulated service evaluations substantiating equivalent risk and life expectancy have been well documented. In the absence of such test results, allowing a lower safety factor or higher design factor is not in the public's best interest.

WRP, Inc., a water utility created to jointly serve South Walton Utilities and Destin Water Users needed to construct approximately 16 miles of water transmission main to deliver water from well fields north of their primary service area to the coastal areas of the Florida panhandle. The alignment for this transmission main required traversing multiple creeks and wetlands, one major roadway, several developed areas, and a 3-mi subaqueous crossing of Choctawhatchee Bay. The required flow capacity and hydraulics of the pipeline necessitated a nominal 30-in. pipe size, making the difficult installation components even more challenging. As an additional challenge the project had a one-year construction window to allow for a Florida Department of Transportation widening project. Polyengineering, Inc., the design engineer for the project, evaluated the challenges and complexities of the project and recommended a value engineering approach to deliver the required functionality with the most favorable economics. Based on an initial matrix of pipe materials and construction methods, a short list of available options that would satisfy the design intent was developed for contractors to bid. A combination of traditional open cut, horizontal directional drilling (HDD), jack-and-bore, and marine trenching installation methods would be considered. For the open cut sections, ductile iron pipe and polyvinylchloride (PVC) pipe would be considered; for HDD sections, fusible polyvinylchloride pipe (FPVCP), high-density polyethylene (HDPE), and restrained joint ductile iron pipe would be considered; for marine crossing sections, HDPE and restrained joint ductile iron would be considered. This paper will focus on the combination of materials and construction methods that were utilized to address the significant engineering design and construction challenges to deliver the hydraulic and economic performance necessary for a successful project.

The Natomas Mutual Water Company's (NMWC) Sankey Diversion Project included a 434 cfs fish screen and pump station (Diversion) to divert water from the Sacramento River into an abovegrade irrigation canal on the landside of the Sacramento River levee. The pump station's five 48-in.-diameter welded steel discharge pipes are routed over the top of the river's flood protection levee at an elevation substantially higher than the canal water surface (discharge point). A complementary vacuum system was installed to reduce the pressure in the pipeline at the top of the levee and thereby reduce the total dynamic head and power consumption for the pump station. Early testing shows a 48% reduction in power use due to the vacuum system—a considerable savings because at least one 400 HP pump (and often three) runs 24-7 for months at a time. This paper presents the design concepts and components of a vacuum system with emphasis on vacuum piping requirements and mechanical systems integration. Design, installation, and startup of the vacuum system and associated piping at the Sankey Diversion Project will be reviewed, including operational control strategies.

The East Bay Municipal Utility District (District) is a major metropolitan water district located near San Francisco, California. The District recently completed the planning and design for the Dingee Pipeline and Claremont Center Aqueducts Replacements Project, a $22 million project that includes replacing a 2.3-mi segment of an old transmission pipeline, which delivers water to more than 18,000 customers, and 0.6 miles of aqueducts that serve treated water to more than half of the District's 1.3 million customers. This crucial project will replace aging pipelines that have a history of leaks and customer service disruptions. Sequencing and scheduling is a critical component of this project so that required outages of major pipelines are performed efficiently and within a short window of time to minimize community impacts and reduce water service interruptions during construction. This paper highlights the myriad planning and design challenges associated with implementing a major pipeline replacement project in a congested and populated urban setting.

This paper presents a nonoscillatory model based upon the two-component pressure approach (TPA) model, which is utilized for calculating transient mixed flow in pipelines. The proposed model uses a first-order Godunov numerical scheme with an approximate HLL Riemann solution. It is shown that to remove the numerical oscillations the numerical viscosity of the scheme should be enhanced, particularly once the flow transition changes the regime from open channel to pressurized flow. To accomplish this goal an algorithm is proposed to improve the wave structure of the numerical scheme based upon which the HLL solver estimates the mass and momentum fluxes. The proposed algorithm significantly increases the scheme's numerical viscosity whenever flow transitions tend to occur, while it otherwise admits an optimum numerical viscosity. The performance of the model is numerically explored and verified through several test cases.

Much of Astoria, including the 30-block project area, is constructed over slow-moving earth flows that result in ongoing ground deformations. Within project limits, a new stormwater conveyance system bypasses the sanitary interceptor, eliminating untreated combined storm and sanitary overflows into the Columbia River. The project included 12,600 ft of storm, 1,500 ft of sanitary, and 4,900 ft of water pipelines constructed entirely within an urban residential area and routed across two large, active landslides. Other challenges included extreme slopes, shallow groundwater, and groundwater springs surfacing through pavement cracks. Comprehensive risk assessment and management of these challenges was achieved through careful geotechnical and civil planning and design. Included were geologic research and mapping, strategic selection and placement of pipeline materials like HDPE pipe and flexible fittings, and a permanent groundwater collection system. The final design accommodates ground movement and controls groundwater, providing the City with a longer useful service life for the pipelines.

Welded steel wye branches are a key component of most water projects where flows must be divided. They are also a specialty item that requires many engineering considerations. The design of wye branches has been studied by many agencies over the years and good design guidance can be obtained from several sources including the American Water Works Association's (AWWA) Manual M11, Steel Water Pipe: A Guide for Design and Installation, where the focus is determination of proportions of steel reinforcement necessary to resist internal pressure. However, welding details for wye branches is often left to the fabricator, and little guidance is offered. Selection of proper welding details requires a high degree of skill on the part of the fabricator to complete the design and to make it function reliably as a safe, integral part of a conveyance system as intended by the designer. Welding details for complex pipe fittings such as wye branches are not published elsewhere, and fabricators are on their own to make these structures work; there is no common methodology for analysis and design of groove welds that are key structural components of wye branch crotch plates. Often welding details are left to the poor welder actually doing the work, but most welders are not engineers so owners of wye branches end up with "potluck" without adequate engineering oversight. The author is aware of failures attributable to faulty welding details. This paper will address several areas of wye branch fabrication that are not well covered by other sources including local dihedral angle and groove weld bevel determination and weld joint detailing. Weld joint geometry is complex and graphs for determining local dihedral angles for common 90 degree and 45 degree pipe intersections are presented as an aid to the designer of wye branches.

Design of rehabilitation and replacement of 10 mi of water distribution mains in an urban environment can be challenging. The water mains replaced for this project are part of the City of Baltimore's holistic approach to proactively update its century-old water distribution system. The City's critical distribution system includes more than a thousand miles of pipe that have reached or surpassed their useful life; many of which have failed in recent years resulting in major disruptions to the City's customers. Pipes slated to be replaced were installed in the late 1890s and early 1900s, with the majority installed prior to the 1930s. The mains are composed of varying materials, including both pit-cast and spun-cast DIP. This paper focuses on unique challenges associated with the evaluation and design of water mains in an urban environment that have been in service for more than a century.

The San Diego County Water Authority (SDCWA) is a wholesale water supplier to 24 agencies in the San Diego, CA, area, serving a population of more than 3.5 million. Approximately 82.5 mi of the total 300 mi of pipe in the system is prestressed concrete cylinder pipe (PCCP). 1979 marked the first catastrophic failure of a 19-year old section of PCCP. To ensure that the Water Authority fulfills its mission statement, "to provide a safe and reliable supply of water to San Diego County," the Aqueduct Protection Program (APP) was instituted in 1992 with a primary focus of preventing premature failure of the 82.5 mi of PCCP and extending the overall service life of the PCCP system. The initiatives undertaken by the Water Authority as part of the APP have been pioneering and have been closely followed by owners of PCCP systems both nationwide and around the world. The rehabilitation of the PCCP system comprises the use of collapsible steel cylinders as a long term structural solution, extending the service life of a line by 75 years. This paper begins with a detailed look at the history and performance of PCCP in SDCWA's transmission system, which then leads into a historic review of the Aqueduct Protection Program, how and why it came into being, covering all substantial initiatives that have been undertaken to date. A clear understanding of the sustainable approach to extending the service life of the agency's PCCP lines is given. As a pioneer in the use of collapsible steel cylinders to achieve a fully structural renewal of deficient PCCP lines, the Water Authority has played a key role in the evolutionary development of the design and installation of these steel reliners. Design methods and technological developments have iteratively improved cylinder fabrication, installation processes, and quality control protocols, all of which are discussed. A case history of the ongoing Pipeline 3 Relining, Sweetwater to Lower Otay, is provided to illustrate many of the topics discussed.

The paper investigates the pattern of soil stress around a pipeline installed under the river using a nonlinear three-dimensional finite element method (FEM). This study compares von Mises soil stresses occurring in native soil adjacent to river crossing pipeline between traditional open trench (OT) and horizontal directional drilling (HDD) pipe installation methods. The Mohr-Coulomb theory is utilized to describe soil behavior in the finite element models. The entire model is assumed to be elastoplastic. The whole research considers saturated native soil one month after construction. Additionally, design parameters (i.e., depth of cover and annular space) in HDD method are examined to understand their influence on soil stress occurring around original soil. The paper investigates how critical design parameters (i.e., density and diameter) in the annular space affect the pattern of maximum von Mises soil stresses occurring in native soil adjacent to pipeline installed under the river. Finally this study found that when the OT method is used for pipeline crossing under the river, stress occurring in the soil cover is greater than when the HDD method is used. In addition, the diameter of the annular space in HDD method could impact on total soil stress occurring in the soil overburden.

The City of Phoenix used an alternate project delivery method to complete the Reservoir Interconnect Pipeline at the Deer Valley Water Treatment Plant (WTP). This pipeline provides the City with the ability to operate the two existing 20 million gallon (MG) finished water reservoirs at the WTP. This improved flexibility eliminated short circuiting within either of the reservoirs and allows them to be operated in parallel or independently. The project needed to be completed within a short time frame under challenging site conditions and constraints. The City chose construction manager at risk (CMAR) project delivery method with Wilson Engineers designing the project and Kiewit Infrastructure constructing the project as the CMAR contractor. Many alternative construction materials and methods were evaluated to determine the most cost-efficient, safe, and quality-driven solutions to the project challenges. The interconnect pipeline installation was constrained by a compressed schedule and challenging site conditions. The 96-in. reinforced concrete cylinder pipe (RCCP), manufactured in accordance with the AWWA C300 standard, was installed in soft soil conditions at a depth ranging from 20 to 32 ft between two operating reservoirs 50 ft apart. Two junction structures were constructed to connect the new pipeline to the existing pipelines during the annual plant inspection period. Kiewit collaborated with the City of Phoenix staff and consulting engineer to develop, design, and construct a safe and effective shoring. The chosen system allowed the flexibility to overexcavate unsuitable soils and improve the subgrade to support the pipeline, while allowing unimpeded access to install the pipe. Soils between the reservoirs were continuously monitored during excavation, pipe installation, and backfill operations to ensure the stability of the existing structures. The 96-in. pipe was installed using a mobile trolley type gantry crane system. The trolley was fabricated on site and supported by two concrete foundations placed along the length of the excavation. The pipe sections were swung into the excavation with a crane, picked up by the trolley, and pushed down the trench to its final installed location. Extensive planning, prior to and during the course of construction, resulted in the project being completed and the WTP back in operation ahead of schedule and under budget.

This paper presents the results of a laboratory testing program on the curing behavior of one impregnating epoxy (Tyfo S) and one thickened epoxy (Tyfo WS) that are most commonly used in carbon fiber reinforced polymer (CFRP) repair of pipelines, including progression of cure at various temperatures; relative humidities and relationships between the degree of cure and properties such as hardness, glass transition temperature, and long-term water absorption of these epoxies; and tensile properties of the CFRP. Based on the tests performed, curing schedules can be established to achieve a minimum degree of cure of 85%, which is typically used in practice for newly installed CFRP liners prior to refilling of pipelines. Quality assurance procedures are proposed for verification of the degree of cure achieved in the field, including a project example where the proposed procedures have been used.

This paper presents the results of the experimental phase of a three-year research program sponsored in part by Water Research Foundation (WRF) to form the experimental basis of an American Water Works Association (AWWA) Standard on carbon fiber-reinforced polymer (CFRP) renewal and strengthening of prestressed concrete cylinder pipe (PCCP) that is being developed. The experimental program included full-scale three-edge bearing tests and hydrostatic pressure tests on CFRP-lined PCCP with simulated distress, laboratory testing of CFRP shear bond strength on steel substrate for use in the design of CFRP terminations, and laboratory testing of tensile and flexural ductility of different epoxies used in CFRP liners. A summary of the results of these experiments and their effect on the design, material, installation, and quality control provisions of the AWWA Standard are presented.

This paper presents the results of a three-year research program on carbon fiber-reinforced polymer (CFRP) renewal of prestressed concrete cylinder pipe (PCCP) sponsored by the Water Research Foundation to form the theoretical and experimental basis of an AWWA Standard being developed for the same purpose. The paper identifies limit states related to strength, stability, and watertightness of the CFRP liner considering continual degradations of the host pipe. The design is based on load and resistance factor design (LRFD) approach with load and resistance factors selected to ensure reliability comparable to those of other construction products, material adjustment factors that account for durability, and time effect factor that account for the sustained load effects. The experimental phase of the research program included full-scale three-edge bearing tests and hydrostatic pressure tests and laboratory testing of shear bond strength and resin ductility. The theoretical bases of design are simple design equations the accuracy or conservatism of which is established through comparison with detailed finite element analysis.

The City of Corpus Christi provides water in 11 Texas counties. The City studied three options for increasing its water supply, which included diverting water from the Colorado River, seawater desalination, and constructing a new reservoir. Diverting water from the river proved to be the most efficient water supply. However, river water poses many challenges to owners, operators, and design engineers. Presented herein are three of the major technical challenges associated with the planning and design of the Mary Rhodes Raw Water Pump Station: Challenge No. 1: Construction on Steep Riverbank. Microtunneling proved to be a viable option for this river intake. Many times riverbanks are steep, and the vertical distance to river water is long. For this project, the riverbed is approximately 40 ft below the top of the riverbank. Steep banks and challenging soil conditions make open-cut activities difficult and costly and can have negative environmental impacts. Challenge No. 2: Handling River Water and Sediment. A primary obstacle when pumping river water is removing suspended solids (sediment) from the water. Once the sediment is removed, the next obstacle is disposing of the sediment. Additionally, it is important to design systems and select equipment that can withstand abrasion due to sediment loading while still operating efficiently. Challenge No. 3: Wide Static Range for Pumping Conditions. River levels can fluctuate widely and rapidly during flood events, or due to operations of river-control structures such as dams. These fluctuations create difficult pumping conditions for reliably supplying water to a storage tank or water treatment plant. Storage tanks have minimal storage capacity, and variant static pumping conditions amplify the risk of overflowing a tank. Designing a reliable system to operate under all conditions is crucial for water supply. Each of these challenges influences the final design of this project. The design process focuses on innovatively accommodating the factors pertinent to each of these challenges to produce an optimized solution balanced in efficiency, reliability, cost effectiveness, operational ease, and environmental impact.

The East Bay Municipal Utility District (EBMUD) is a major metropolitan water district located near San Francisco, California. Approximately 90% of the EBMUD water supply is conveyed by three 82 mi (132 km) long pipelines, the Mokelumne Aqueducts, from the Sierra Nevada to EBMUD's service area. For approximately 10 mi (16 km), the three parallel pipelines are elevated on pile-supported bents across the islands of the Sacramento-San Joaquin Delta, where there is significant risk of flooding and seismic hazards. A significant flood or seismic event in the Delta would likely damage the two oldest and most vulnerable aqueducts, and only the newer aqueduct, which has been seismically upgraded, would survive. To mitigate the risk of failure of one or more aqueducts, interconnections were constructed on both sides of the Delta. The interconnections will increase transmission capacity of the system by 50% by utilizing the capacity of the surviving portions of aqueduct outside of the Delta.

The replacement of the 36-in. diameter sewage force main for the Dundalk wastewater pumping station for the City of Baltimore Department of Public Works poses several design challenges associated with large-diameter pressure mains in congested urban areas. These design challenges include combination pressure and gravity hydraulics, isolation valves, horizontal and vertical alignment deflections, air release, thrust restraint, utility relocations, bypass pumping, poor soil conditions, and possible localized soil contamination. The Dundalk pumping station located on Broening Highway at Keith Avenue in southeast Baltimore was constructed in 1946 and is of conventional wet well-dry pit configuration. The pump arrangement includes three parallel pumps with control valves connected to a manifold and a 36-in. cast iron force main. The existing 4,300-ft force main pumps to a 54-in. gravity sewer. Maximum pumping capacity with all pumps running is 23,000 gpm (33 MGD) at 110 ft total dynamic head. The Department of Public Works has determined that a replacement main is required due to deterioration of the existing cast iron pipe. It is intended that the old main remain functional as a backup to the new replacement main. The initial design challenge is to find a suitable alignment for the new main because the original main is located in a narrow public utility easement through private industrial property. The choice of using the public road right of way for the new alignment results in a longer route and a highpoint about 800 ft from the discharge point and subsequent downhill run. This generates a potential hydraulic problem in the transition from pressure flow to gravity flow. The interconnection of the old and new mains require an isolation valve arrangement near the pumping station so that either main can be operated by a control switch inside the station. Due to limited space between major drainage structures and the existence of a concrete thrust restraint system for the old force main in the area where the dual control valves are to be placed a compact configuration is necessary. The 3,800 ft alignment in the industrial arterial road poses the usual complexity of congestion. Selecting a horizontal and vertical alignment requires intense coordination between field topographic surveys, interpretation of often schematic record drawings, surface marking, and field reviews. Part of the main alignment falls within an area of land reclamation from the early part of the last century. The unconsolidated nature of the fill soil and high water table makes the thrust restraining joint systems a critical element of design.

This paper presents a quasi-two-phase flow model for simulating filling in water pipe systems. The model employs a shock-fitting algorithm for tracing the water column advancement during filling. The method of characteristics (MOC) along with discreet gas cavity model (DCGM) is utilized to capture the possible water column separation and induced water hammer pressures during filling. The state-of-the-art air valve boundary condition is improved to account for the two-phase flow usually established in the pipe on the downstream side of the air valve. The results show that the proposed model can (1) replicate the negative pressure and consequent water column separation; (2) reproduce the secondary transient pressure following the releasing of the air at air valve locations; (3) simulate controlled air release, a strategy usually employed for alleviating the severity of secondary transient events; (4) capture the final steady state flow condition even when the pipe system maintains both open channel and pressurized flow simultaneously; and (5) reproduce air binding and consequent flow reduction in the case that an air valve fails to release the air from the system.

Tarrant Regional Water District (TRWD) and Dallas Water Utilities (DWU) have been in the preliminary and final design stages for the Integrated Pipeline Project (IPL) since 2008. The $2.3 billion IPL is a joint project between Dallas and TRWD and will include 150 miles of pipeline from Lake Palestine to Lake Benbrook. The Line J, Section 1 (LJS1) project is being built for TRWD to supply water to a new hydroelectric generation facility and to meet demands at the Lake Arlington delivery point. An opportunity presented itself to use the LJS1 project as a prototype for the IPL project because the project elements are similar. LJS1 utilizes the same design standards and construction methods that are proposed for the IPL project, so that the lessons learned could be applied to the IPL. The objectives of the LJS1 project included the following: to test the use of on-site mixed controlled low strength materials (CLSM) for the IPL; to test the quality of factory-spun cement mortar lining for 108-in. steel pipeline by multiple pipe manufacturers; to test the design standards (design criteria, specifications, and details) for the IPL program; to evaluate the sustainability of alternate construction methods and materials and apply for an Envision rating; to test the use of real-time GIS as-built systems; to evaluate and recommend improvements for constructability, risk allocation, and contract documents; and to provide a dedicated pipeline for the proposed hydroelectric generation facility and alleviate a bottleneck in capacity of the existing system to meet one of its demands. The LJS1 project includes 12,000 ft of 108-in. diameter steel pipeline, with a construction cost of $19 million. Project completion is scheduled for early 2014. The construction manager at risk (CMAR) delivery method is being used with several bid packages for pipe, valves, tunnels, pipe installation, and tie-in sections. This paper describes the lessons learned for the design and construction phases, with an emphasis on CLSM performance and constructability. Additional topics include pipe manufacturing from four suppliers, the CMAR delivery method, GIS as-builds, and sustainability.

As Texas continues to experience some of the worst droughts in its history, cities that have been proactive in securing water for their future are more prepared for what lies ahead. Corpus Christi is one such city that has worked to diversify their water supply over the years and has put itself in a good defensive position against extreme drought conditions. The City of Corpus Christi (the City) currently utilizes three major water sources to meet the needs of more than 500,000 customers in Corpus Christi and the Coastal Bend. Its latest endeavor to protect the region's population against drought is the Mary Rhodes Phase 2 Pipeline project. This project will be the fourth major water source for the City. The first two sources are Lake Corpus Christi and Choke Canyon Reservoir. In 1993, the City entered into a contract with Lavaca Navidad River Authority to purchase the third water supply. This supply comes from 41,840 acre-ft of water per year from Lake Texana. The Lake Texana water supply was a key acquisition for the City as it supplies approximately 50-70% of the drinking water to Corpus Christi citizens. In 1998, the City completed 101 mi of 64-in. pipeline connecting Lake Texana to the City's water supply system. This water line, known as the Mary Rhodes Pipeline, was designed to include extra capacity for additional water sources. These additional water sources will come from the Colorado River through the Mary Rhodes Phase 2 Pipeline. This project is essential to the region as Lake Corpus Christi and Choke Canyon water levels are currently below 30%. The Mary Rhodes Phase 2 Pipeline will include approximately 42 mi of 54-in. pipeline, a 46 MGD intake pump station, a sedimentation basin, a 46 MGD booster pump station, and a 6 MG GST. The project team is composed of 17 different companies performing design, survey, modeling, and easement acquisition services. Most of these team members are local to the Corpus Christi area but some are spread across Texas and other parts of the country. The design team began preliminary design in 2009, a process that included a route study, permit preparation, and preliminary hydraulics and water quality testing on the Colorado River. Because the City utilized a Water Infrastructure Fund deferred loan, the engineering feasibility report and environmental permitting were completed prior to the beginning of the design phase. Environmental permits were secured in December of 2012, and final design began immediately after. As the drought continued through 2012 and 2013, the City decided that the Mary Rhodes Phase 2 Pipeline system needed to be built immediately to guard against drought for the Coastal Bend's service area. This service includes municipal demand and a growing industrial demand. Because of this water need, the final design phase for this project has been fast tracked to allow for construction to begin in March of 2014 and be completed in April of 2015. The design of the project is currently on track for an October 2013 bid advertisement date, keeping in line with the City's water needs. The Mary Rhodes Phase 2 Pipeline project has incorporated many unique techniques throughout the design phase including, but not limited to, value engineering, prepurchase of equipment, public stakeholder meetings, large-diameter horizontal directional drilling, and microtunneling of intake pipes.

The present paper provides an overview of available tools and provisions for the structural analysis and design of buried welded (continuous) steel water pipelines in seismic areas, subjected to earthquake action. Both transient and permanent ground actions (coming from tectonic faults, landslides, and liquefaction-induced lateral spreading) are considered. Specific issues are discussed on the modeling of the interacting pipeline-soil system using either simple analytical models or nonlinear finite elements, and their main advantages and disadvantages are pinpointed. Subsequently, the resistance of buried pipelines is discussed, with emphasis on possible failure modes. Finally, possible mitigations measures for reducing seismic effects are discussed for the safe operation of steel water pipelines against seismic hazard.

Increasing wastewater flows with decreasing effluent permit limits presented a giant challenge for the Trinity River Authority of Texas's (TRA) Denton Creek Regional Wastewater System Wastewater Treatment Plant (DCRWS). An expanded service area and a change in the water quality modeling protocol used by the Texas Commission on Environmental Quality (TCEQ) forced TRA to look for alternative discharge points to distribute the load being discharged from the DCRWS. TRA examined options within the system and took advantage of two developing pipeline projects that allowed postponed expenditures/cost sharing, achievement of anticipated effluent limits, and operational flexibility. The project includes approximately 9 mi of influent and effluent pipelines ranging in size from 16 to 48 in. This paper discusses how TRA changed planned infrastructure improvements to creatively meet the future wastewater conveyance needs of the system while providing operational flexibility and meeting changing discharge requirements.

Many of the projects we work on involve welded steel pipe and related structures. Yet, as engineers and pipeline designers, the majority of us have not received in-depth training on how to read welding codes, interpret welding procedures, understand nondestructive testing methods, or evaluate the best methods to accomplish a particular welded joint geometry. We are taught how to calculate weld strength, but the means and methods needed to convert a symbol on a design drawing to a completed weld that passes inspection are typically not well understood. By clearly conveying project welding requirements the engineer, shop fabricator, and contractor can avoid misunderstandings, thereby reducing contractor resubmittals and engineering review times. The desired goal is to ensure that the engineer gets the weld strength he or she is counting on, and the contractor has a clear understanding of the welding code and contract requirements that need to be met.

This paper discusses an experimental study on the pipe rehabilitation method for the purpose of establishing a fundamental design standard. In this method, as the new pipe is directly inserted into the aging pipe, there are several possibilities in terms of cost reduction. It is not clear how the damaged outer pipe mechanically influences the inner pipe through interaction with the surrounding soil when an external force is applied to the ground. In this study, centrifuge model tests for the buried pipe are carried out. The test results indicated that deformation mode of the new pipe largely depends on the damage level of the outer pipe. When the damage state is not serious, the outer pipe protects the inner pipe from deforming and behaves positively. However, the outer pipe, if at ultimate limit state, has almost no influence on the mechanical behavior of the inner pipe. Additionally, the concentration of stress within the inner pipe tends to occur at the position where there is cracking of the outer pipe in a certain damaged condition.

Hydraulic design of piped gravity sewer systems needs to be optimized for stipulated design guidelines. Though separate systems for transporting storm run-off and sanitary flows are preferred, many cities are forced to use combined sewer systems to jointly transport both flows. Faulty and ad hoc design concepts can undermine sewer hydraulics and lead to flooding. At times, maximum depth of excavation for new sewers is stipulated at the project outset based on site conditions like congestion, soil characteristics, adjoining existing infrastructure, constructability, space constraints, and socioeconomic and environmental aspects. This paper summarizes a set of evaluation parameters used to assess the efficiency of a system's hydraulic design, including equivalent diameter (D_e), pipe utilization factor (f_PU), equivalent slope (S_e), equivalent invert depth (I_e), and equivalent velocity (Ve). The approach delineated can be a tool to ensure consistency in design, eliminate surcharge, and reconcile competing system operational constraints.

The City of Dallas is bisected by the Trinity River, which flows southwest of Downtown Dallas. During the early 20^th century the city was flooded by the river and a system of two levees was constructed in the 1930s to form the Dallas Floodway and control the river. The system was improved by the U.S. Army Corps of Engineers (USACE) in the 1950s, and the Dallas Floodway became a federal project. There are six pump stations that are part of the associated interior drainage system: Able, Baker, Charlie, Delta, Pavaho, and Hampton storm water pump stations.

The City of Irving is located in North Texas, near Dallas/Fort Worth, and serves a population of more than 218,000 residents. Like many municipalities, the City of Irving increasingly relies on aging infrastructure to meet customer demands. Urban growth and development and public perception are some of the major challenges in maintaining and replacing existing infrastructure in highly populated regions. To meet increased demands and improve the City's infrastructure, the City of Irving initiated a project to replace an existing 18 in. to 24 in. wastewater line with a 36 in. to 42 in. wastewater line in conjunction with increasing the capacity of a storm drain channel. The design also included collection of flows from services and incoming lines along with removal of a siphon on an existing collection line and removal and abandonment of existing lines. This design would also provide for the ability to eliminate a 15-in. siphon that branches off of the Delaware Creek line. These improvements were necessary to fully utilize improvements to the system that had been previously made downstream and would rid the owner of 50-yr old clay wastewater pipe between and underneath houses and a corroding 30-yr old concrete wastewater pipe. This paper will focus on the major planning, design, and coordination challenges through the design of the project from both the owner's and the designer's perspectives. Unique project issues include coordination of multidiscipline design; coordination of channel and utility infrastructure throughout the narrow, developed corridor; crossing of load-bearing channel walls and bridged structures; geotechnical concerns due to high water table and compaction near channel walls and manholes; public perception; odor control; access; and construction sequencing.

The Southern Delivery System (SDS) is a Colorado project to bring water from the Arkansas River to Colorado Springs, the City of Fountain, the Security Water District, and the Pueblo West Metropolitan District. Phase 1 of this two-phase project includes all of the components necessary to begin delivering water to the partner communities by April 2016. SDS Phase 1 construction commenced in 2010 with water delivery expected by April 2016. Core components include a reservoir connection at the North Outlet Works of Pueblo Dam, approximately 50 mi of predominately 66-in. diameter water pipeline, three raw water pump stations with ultimate capacities from 78 to 100 million-gallons- per-day (mgd), and a 50 mgd water treatment plant and finished water pump station. A critical component of the raw water transmission system is a hydraulic transient (surge) mitigation system that was designed to protect the raw water transmission system from damaging pressure surges associated with abnormal operating conditions. This paper will discuss initial planning and establishment of project-wide surge parameters, value engineering (VE) of the surge system, and final modeling and design. A project the size of the SDS requires years of planning prior to final design and construction. For surge mitigation, conceptual design efforts began at project inception to define basic surge performance criteria and general mitigation strategies. This effort was especially important on the SDS because Colorado Springs Utilities anticipated that multiple design firms and contractors would be involved in delivering the project over several phases. The conceptual design resulted in a surge mitigation strategy that included pressurized hydro-pneumatic surge tanks at the pump stations as the primary surge mitigation system. A continuous focus of the SDS is maximizing value to the project's ratepayers, which was realized through a comprehensive VE study. As the pump stations entered final design, the project team initiated the VE study that included the surge mitigation system. The study identified numerous potential VE items and evaluated the benefits, drawbacks, and potential cost savings of each item. This collaborative effort included design engineers; construction professionals; and management, engineering, and operations staff from Colorado Springs Utilities. The VE process continued through design until all ideas identified by the project team were exhausted. Final surge modeling was then completed to finalize design of the system. Modeling was performed using commercially available wave-characteristic-based hydraulic modeling software. Particular modeling parameters that became important in the modeling effort were the interaction and configuration of critical air valves on the pipelines and the inlet/outlet configuration of the tanks. By taking a proactive approach to surge design, Colorado Springs Utilities is taking the necessary steps to protect a major investment in the security and reliability of the region's water supply.

The City of Port Angeles required three pipelines to deliver effluent sewer to a water treatment plant as part of a combined sewer overflow (CSO) diversion project. An abandoned existing partially buried 48-in. reinforced concrete waterline that runs the length of the Port Angeles waterfront was used to rout the required force main pipelines to reduce disturbance to sensitive areas including Native American burial grounds, protected coastal species habitat, and high-quality wetlands. A pipe bundle consisting of two 14-in. and a single 30-in. pipe were sliplined through the existing waterline using a horizontal directional drill rig. Complex transitions from grade to subsurface elevations in tidally influenced zones of protected shoreline complicated the design and installation at the slipline pull and insertion pits. The 4,500 lineal ft slipline design is detailed along with specific challenges that required unique solutions both in design and during the construction.

Since 1999, Tucson Water has had an active PCCP asset management program utilizing inspection and advanced structural materials such as carbon fiber. The program strategy includes precision inspection methods that identify distressed pipe segments and proactive rehabilitation of those segments. In January 2013, separation of several pipe segments located at bends in an 84-in. PCCP line was identified. The separation of the joints was due to combined loading issues at the bends, specifically inadequate thrust restraint. The pipe sections with inadequate thrust restraint were strengthened using carbon fiber primarily applied in the longitudinal direction to address the identified issues. The use of the trenchless repair method was favorable due to the difficulty of excavating in the distressed pipe region. The application of carbon fiber for this design condition was a significant advancement beyond typical CFRP rehabilitation, which involves reinforcement primarily in the hoop direction. This paper will provide valuable information and insight into the use of CFRP to address thrust restraint.

The Balch Consolidation Conduit (BCC) was operational at the end of 2011 to meet the City of Portland's Bureau of Environmental Services' (BES) Amended Stipulation and Final Order (ASFO) from the Oregon Department of Environmental Quality. The ASFO outlined staged reductions in the combined sewer overflows (CSO) to the City's waterways. The BCC consolidation pipelines were constructed to convey CSO flows from NW Portland to the larger Westside CSO (WSCSO) Tunnel. The City's CSO Tunnel System contains two large tunnels and numerous large-diameter connecting consolidation pipelines. Evidence of transients and air entrapment issues in the CSO collection pipelines initiated a study of the CSO Tunnel System consolidated pipelines. The study results focused and recommended areas for improvements to protect the system from surge forces and air releases. This paper will discuss the field reports, larger system study findings, and resulting projects.

Waste disposal sites require subsurface gravity pipe systems to collect waste leachate and safely convey it to treatment and disposal facilities. As the availability of suitable land for waste disposal sites decreases and the cost to design and operate these facilities increases, the need to maximize waste storage capacity grows. The result is an ever-growing demand for deeper fill heights for both new and existing disposal sites. Of critical importance is an understanding of the structural adequacy of the leachate pipe, which must resist soil overburden pressures of up to several hundred feet. This paper discusses the engineering parameters that must be considered when evaluating the structural capacity of deeply buried flexible pipe for leachate collection, including waste material unit weight, soil stiffness modeling, arching factors, pipe bedding and backfill conditions, time effects, and design safety factors. Limit states that govern deeply buried pipe capacity include axial thrust, global buckling, ring bending, and diametrical deflections. The relative accuracy of current design methods and finite element analysis are evaluated, and modeling caveats are discussed. An example analysis of a deeply buried pipe installation is presented using the finite element program CANDE to estimate vertical arching factors.

The City of Gillette is undertaking a $220 million project to serve the region with a reliable, long-term water supply. The project includes wells, treatment, transmission and distribution waterlines, pumping, and storage. The Gillette Madison Pipeline Project (GMPP) will allow the City of Gillette to serve the water demands of its rapidly growing population, which is driven by energy development in the Powder River Basin. The project will provide redundancy and reliability to the backbone of the City of Gillette infrastructure for service to its customers well into the future.

A large water supply pipeline has been designed to carry water from the Willamette River in Gladstone, Oregon, to the cities of Lake Oswego and Tigard, Oregon. The pipeline ranges in diameter from 24 to 48 in. and traverses more than 10 mi. The pipeline was part of an overall water supply project that included a raw water intake, a raw water pipeline, a water treatment plant, a finished water pipeline, and a reservoir. Finding a route for the pipeline was challenging as it traversed through many cities and required a number of interagency agreements. Along with the routing challenges, there were many technical challenges such as crossing beneath the Willamette River. This crossing is 36-in. in diameter through basalt that varies in unconfined compressive strength exceeding 40,000 psi. An extensive trenchless evaluation was performed to determine the method that offered the highest chance of success with the lowest overall risk profile. Horizontal directional drilling (HDD) was chosen as the preferred trenchless installation technique. The length of the river crossing is 3,800 ft, making the 36-in. diameter rock drill very challenging. In addition to the challenges of the drill, site and pipe layout was very restricted, further complicating and increasing the risk of the project. Many aspects of the drill had to be thoroughly laid out during design, leaving little flexibility to the contractor. This paper discusses the design of the project, the risk aspects of the horizontal directional drill and microtunneling alternatives, and the decision process leading to the selection of the trenchless technology.

Due to economic or other reasons, natural gas transmission pipelines are sometimes constructed in regions susceptible to geohazards such as mud flow, soil creep, and landslide. Although it is possible to design a pipeline to withstand these ground movements, it may not be cos effective to install kilometers of high-grade thick-wall steel pipe traversing a mountainous region. Furthermore, some areas may not appear to be prone to soil movement or may not show visible signs of slope instability at the time of pipeline design and construction. In this case, a section of buried pipeline on a hillside in Colombia was affected by gradual ground movement resulting in buckling of the pipe at the pipe bridge located at the foot of the hill. Repairs were carried out by replacing the buckled section of pipe with a new pipe and cutting the pipe at the top of the hill to relieve tension developed in the buried pipe. Survey markers were installed across the hillside to monitor future ground surface movement. Following the repair, as part of the pipe integrity management plan, the pipeline operator wanted to know where to install strain gauges to monitor pipe stresses, where to install inclinometers to monitor future land slips, and the amount of ground movement allowable before intervention is required. This paper describes how the pipeline operator's requests were achieved by applying multiple analysis techniques. First, the available geotechnical and geological data from the site was reviewed. A representation of the slope was created in a finite element model and a strength reduction procedure was used to estimate a number of significant slip surfaces corresponding to various slope stability factors. The soil movement profile was then normalized and applied as movement perturbation to a three-dimensional finite element pipeline model, which had the appropriate nonlinear interaction between the buried pipe and the surround backfill soil, and the pipe support and connection constraints at the pipe bridge. The pipe stress analysis revealed several critical locations where the peak stress as a function of soil movement was then determined. The computed results gave a good correlation to the observed pipe bridge failure thus giving confidence in the pipeline model and provided useful information for the implementation of the monitoring works.

A more precise method for evaluating the seismic behavior of jointed buried pipes networks is presented considering the connections' nonlinear behavior and the main line-branches interaction. Desired network consists of ductile iron pipe segments of 6 m length with diameters of 150, 200, and 300 mm. Elbow and culvert connections are of bolted-gland type, and the remainder is of socket-spigot type. Ductile iron strain stress behavior was assumed as bilinear for performing a series of finite element (FE) analyses on various connections by inclusion of pipe-gasket interaction. First, the connections were modeled by FE method to obtain their hysteretic behaviors. Then, a network, containing three branches, was modeled by beam elements, connected to each other and to the supports by bilinear 3-D springs. The network was analyzed subjected to three-component selected records, considering the time lag between the nodal inputs and various incidence angles. The obtained maximum strains along the pipeline and relative displacements and rotations at connections show that failure of connections is more likely in pipes with larger diameters. Moreover, the existence of branches leads to increase of damage to the network components, particularly to pipes with larger diameters.

The San Diego County Water Authority operates and maintains the San Diego region's aqueduct delivery system, which consists of approximately 483 km (300 mi) of large-diameter pipelines, more than 1,400 aqueduct-related structures, and more than 100 flow-control facilities. These facilities occupy approximately 567 ha (1,400 acres) within the Water Authority's right of way and deliver water to more than 3 million residents. With a significant proportion of its infrastructure approaching the end of its useful life, the Water Authority embarked on an effort to strategically manage its assets over the long term. This commitment will ensure it maintains its mission of providing a safe and reliable supply of water to the San Diego region via its 24 member agencies. This paper will examine the steps taken by the Water Authority to establish an asset management program, including how it classifies and manages asset groups. It will describe, using a risk-based approach, how priority projects are identified and funded. The paper will also discuss the methods used and complexities involved with delivering the projects to ensure a sustainable approach is taken to managing pipeline infrastructure.

While data have become more available over time, transforming raw data into insight remains a bottleneck in the knowledge-generation process. Recurrent analytical reports require a series of repetitive steps including data gathering, validation, processing, quality checks, and finally, a report with the interpretation of observed trends and other analytical summaries. Conventional continuous reporting solutions often require sacrificing either scalability or flexibility. This paper describes a framework for the continuous production of technical reports based in R, Jenkins, and Git open-source technologies. The proposed framework provides an interactive analytical environment suitable for data exploration in constantly evolving projects, while allowing implementing robust software when reaching acceptable long-term analytical solutions.

Over the past 50 years, the San Diego County Water Authority (Water Authority) has experienced nine catastrophic pipe failures. These failures occurred on pipes ranging from 48-in. (1,220 mm) in diameter to 96-in. (2,400 mm) in diameter and had significant consequences. Lessons learned from these failures brought about continuous improvements in design, construction, and operation of pipelines both at the Water Authority and in the industry. This paper describes all nine pipe failures including pipe design, probable failure causes, impacts, and costs. The paper will summarize the failures to evaluate lessons learned, overall trends, and resulting improvements.

Modern urban society depends heavily on lifeline systems such as water supply. A continuous supply of water is even more important during times of earthquakes and other calamities. Seismic ground movements caused significant damage to water supply systems during the Northridge (1994), Kobe (1995), and Christchurch (2011) earthquakes. This paper presents a framework that will enable water utility departments to assess and improve water supply system resiliency against liquefaction-induced ground failures using hazard maps. The developed framework is demonstrated on the water supply system in Charleston, South Carolina. Improving resiliency of the Charleston Water System begins with an analysis of the current structural health of the system. A 10-year water main break data set is used to assess the current health of the system. A liquefaction potential map is then used to identify the most vulnerable areas of the system during future seismic events. Recommendations are made on how to improve resiliency of the Charleston Water System based on innovative and sustainable techniques implemented in other seismic prone areas of the world.

The North Hudson Sewerage Authority owns and maintains a combined sewer system including twin 48-in. outfall sewers that date back to the Civil War. In general, both outfalls are tidally influenced and completely inaccessible. Both outfalls had fallen into such a state of disrepair that traditional and state-of-the-art mechanical and hydraulic pipeline cleaning tools could not even be used to investigate and assess their condition. Specifically, impenetrable amounts of hard sediment, calcification, and tuberculation had choked these grey iron pipelines to such an extent that the only viable solution was direct hand-mining of these calcified pipes with pneumatic chipping hammers to reopen and restore their full diameter. Further complicating the rehabilitation were the deflections, large cavities, transitions, and curves in the outfalls as they crossed below a very large and active rail yard. A cured-in-place pipe liner was ultimately chosen from a wide range of technology options to structurally reline the outfalls. Rehabilitation of each outfall also had to take place while keeping at least one in service beneath 18 active and parallel New Jersey Transit Rail tracks at the Hoboken Terminal. The greatest value for the Authority in terms of long-term infrastructure improvements and incorporating sustainable design was the extended service life combined with significant increase in conveyance capacity to prevent future wet-weather flooding of the combined sewer system. The use of CIPP trenchless solutions provided a cost-efficient alternative to a nearly impossible replacement or relocation strategy that would have required major disruptions to the City of Hoboken, the New Jersey Transit, and other critical transportation infrastructure. Ultimately, the project was completed with virtually no disruption to these critical assets.

Energy efficiency is currently a hot topic on all regional, national, and global stages. Accurate measurements on how energy is being used over a period of time can improve performance of the drinking water utility substantially and reduce energy consumption. Nevertheless, the drinking water industry does not have a specific benchmarking practice to evaluate its energy performance of the system. Therefore, there are no standards to compare energy use between water utilities that have a variety of system characteristics. The goal of this research is to develop a quantitative approach to select energy benchmarking parameters of the water system, so the utilities can use those parameters to improve their energy efficiency. In contrast to a typical drinking water utility benchmarking, the energy benchmarking can specifically compare energy efficiency of a utility with other utilities nationwide. The research developed a regression model based on the statistical representation of the energy use and descriptive characteristics of the drinking water utilities data throughout the United States. All possible regressions was chosen as the parameters selection methodology to identify a subset of most significant parameters, i.e., system characteristics, that can mathematically correspond to energy use across different utilities. As a result, the energy benchmarking would be able to calculate the predicted total energy use of the system from given system characteristics.

In December 2011, a large utility owner in Texas experienced two major sanitary sewer pipeline failures on a 48-in. sanitary sewer main. Emergency design was completed within three weeks, and construction was completed within 90 days with the replaced 48-in. sewer main back in service in April 2012. This municipality serves nearly 1.3 million people and more than 400,000 wastewater customers in Texas. Like many large urban wastewater providers across the nation, the municipality is responsible for the maintenance and rehabilitation of aging infrastructure. This entity maintains and operates more than 5,200 mi of 12-in. and larger diameter pipe in the collection system and three wastewater treatment plants. This paper will focus on the fast-track emergency design and construction of more than 4,800 linear ft of 48-in. sewer pipeline replacement within a heavily traveled roadway. Unique project design issues included double-barrel siphon and air jumper design, temporary siphon structure and operational sequencing, hydraulic analysis and modeling, pipeline trench design, and a condensed design timeline. Challenging construction issues included two separate roadway contracts for construction sequencing; expedited submittal reviews; limited working area; traffic control; accelerated materials delivery; flowable fill requirements; and coordination with city, county, and state agencies.

The Southern Water Supply Project (SWSP) is a system of water transmission pipelines that convey raw water to 10 municipal water providers in northern Colorado. The SWSP is owned, operated, and maintained by Northern Colorado Water Conservancy District (Northern Water). The project consists of 110 mi of tape-wrapped, mortar-lined steel pipe ranging in diameter from 45 in. to 16 in. with design pressures up to 350 psi. The first phase of the project was put into service in 1995. While the initial pipeline was sized to deliver water by gravity, rapid population growth during the late 1990s and 2000s required adding a series of pump stations to boost the system capacity. SWSP has now been delivering water for 18 years. During this time, the methods for monitoring, operating, and maintaining this important transmission pipeline have evolved as experience has been gained. The project has a sophisticated SCADA system that monitors and controls the system and deliveries to the water providers. Operations and maintenance staff regularly monitor the cathodic protection system and regularly maintain the appurtenant structures throughout the system. The positive result of these proactive actions has been a highly reliable system that has virtually no unscheduled downtime. This paper will describe the SWSP, discuss the operations and maintenance of the system, and give perspectives on lessons learned after 18 years of operations.

An extensive, detailed survey of users of high-density polyethylene (HDPE) water pipe in the United States and Europe and of manufacturers of appropriate products has been conducted to determine the practicality and effectiveness of in-service field repairs of the HDPE pipe, including both fusion and nonfusion techniques. As a result of the study, commercially available mechanical (nonfusion) repair fittings and methods that have been successfully employed have been identified, based on their relative convenience and reliability. The present study focused on water distribution pipelines and force mains of sizes 2-in. through 16-in.

This paper discusses a new dual nose isolation tool to perform double block and bleed tapping and plugging to isolate sections of pipe for repair or modification. This tool accomplishes the work in a shorter time than other double block and bleed methods, while retaining the greater safety inherent in a double block and bleed system. The trailing plugging head of the tool forms the primary seal. The other plugging head provides a secondary seal that is fully capable of withstanding line pressure if the primary seal leaks. This is particularly important when it is necessary to manage fluids with dangerous characteristics such as those having ammonia and hydrogen sulfide. The effectiveness of this new tool has been established by the results of more than 480 successful isolations that have been performed with its use around the world over the past several years. Some examples illustrating the use of the tool are provided.

Trinity River Authority's Central Regional Wastewater System Plant is located in Grand Prairie, Texas, near Dallas/Fort-Worth (DFW) International Airport. The system has nearly five miles of in-plant drain lines collecting return flows from all across the plant through one 60-in. drain line emptying into the influent pumps stations. An assessment of the inplant drain line system was underway in the preliminary design phases when an unrelated construction project uncovered the manhole access to this 60-in. drain line, and the contractor notified the assessment team of severe signs of corrosion. A manned inspection was performed, and the inspection revealed that the pipe was nearing collapse. TRA declared an emergency repair and immediately started the process of approving funds for construction. The emergency portion of the project was successfully completed in less than two months. This project highlights the importance of keeping in mind that as asset management plans are being implemented and put in place, sometimes a troubling asset can require special attention. Therefore, it is important to have an emergency action plan in place in the case that an asset rehabilitation is elevated to emergency status.

Zinc metallizing with a high-purity zinc wire has been utilized for external corrosion control of iron pipe for more than 50 years. This paper summarizes publications and experiences of metallized zinc on iron pipe over that time period and discusses advantages and limitations of this method of corrosion protection. Advantages include but are not limited to uniform cathodic protection of the iron pipe surface; thicknesses compatible with critical joint tolerances; no special considerations with respect to field cuts, tapping saddles, or corporation stops; no special handling or installation procedures required; ability to "self-heal" in many environments; minimal surface preparation required; and compatibility with current ductile iron pipe manufacturing processes. Limitations include that it is not recommended as a standalone method of corrosion control in severely corrosive soils or areas of stray electrical currents, it has limited cathodic protection at large areas of unrepaired damage in that it is a sacrificial coating that sacrifices itself to protect the iron substrate, and it is not compatible with some polymeric topcoats. In severely corrosive soils or areas of stray electrical currents, polyethylene encasement conforming to AWWA C105 is used to supplement the metallic zinc coating. Previously unpublished results of corrosion studies, with and without polyethylene encasement, are also presented.

Pull-off adhesion testing per ASTM D-4541 is a commonly used quality control check for coatings on large-diameter steel water pipe. During the testing a metal dolly is glued to a pipeline coating then pulled off to assess adhesion of the coating. In practice, results are very sensitive to circumstances and have large standard deviations compared with their mean value. It is clear from a simple inspection of Griffith's equation for the strength of materials that the pull-off stress at failure increases with the stiffness of the materials and the interfacial failure energy and is diminished by the presence of existing cracks or flaws. Finite element stress analysis explored the effect of the coating and glue stiffness and some of the other possible reasons for variation in the results, i.e., pipe curvature, misalignment of the dolly, and the effect of scoring through the coating and glue around the dolly. The tensile modulus of three polyurethane coatings, an epoxy adhesive, and a cyanoacrylate adhesive were measured and showed that it was possible for a polyurethane coating to be stiffer than an adhesive used to fix the dolly in place. The location of the maximum strain, in the glue or the coating, was used as an indicator of where the adhesive failure was likely to occur within the overall joint. Results indicate that the influence of dolly misalignment on the coated pipe is greater than the influence of the pipe curvature itself. If the dolly was aligned perfectly, the greatest strain and thus most likely location of failure was on the crest of the pipe at the pipe-coating interface. The value of the strain was not a strong function of the curvature of the underlying pipe surface. If the dolly was misaligned, then the locus of failure shifted to where the glue was thinnest, but remained at the coating-pipe interface, if the glue is stiffer than the coating. However, if the coating was stiffer than the glue, then the location of the two greatest strains indicated that failure was more likely to be at the glue-dolly junction in all cases, rather than at the coating-pipe interface. Users should be aware of how these, and other possible, variations affect the pull-off results if they rely upon single dolly pull values to assess the overall adhesion or use the test method to assess the likely reliability of a coated steel pipe in service.

Large amount of sewer manholes in the United States are facing serious structural decays and are in need of immediate rehabilitation. Among various candidate techniques, spray-on lining is one of the promising techniques for no-dig manhole rehabilitation. Based on a new manhole rehabilitation classification system proposed by the authors, epoxy lining is considered as semistructural material and relies on residual strength of existing manhole structure to withstand external loads. Prediction of structural capacity of epoxy-lined manhole structure is a challenging task as the mechanism of epoxy lining reinforcement is not clearly understood. In this study, first laboratory tests on concrete cylinders and beams lined with epoxy lining were performed to evaluate structural performance of concrete with epoxy lining. The laboratory testing provided measurements of basic mechanical properties of concrete and epoxy. However, the lined manhole structures in the field conditions cannot be accurately represented by laboratory testing. Finite element modeling (FEM) using ABAQUS software was used to simulate epoxy-lined concrete members in the field loading conditions. Computer simulation is able to analyze how structural capacity of epoxy-lined manhole is affected by mechanical properties of epoxy, such as flexural strength, elongation, adhesion, and thickness. Results show that FEM simulation can be used to analyze, predict performance, and design epoxy lining for deteriorated manhole rehabilitation.

Owing to the fact that no two projects are alike, more data and metadata are required to perform accurate cost estimates to fit a broader range of circumstances, including comparing traditional and trenchless methods. Contemporary cost-estimating practices for drinking water and wastewater pipeline condition assessment and renewal engineering projects are based on limited and incomplete datasets. Historically, data and metadata of this nature required great expenditures to collect, normalize, and use in an efficient manner. Recent developments in computing have created the ability to collect, standardize, and analyze high-quality project cost data in an automated manner, preparatory to visualizing this data in a Web-based, geospatial tool. This research focuses on the development of database and tool for collecting, standardizing, viewing, and estimating drinking water and wastewater pipeline condition assessment and renewal engineering direct and societal costs in an online interface. Data were retrieved from 82 participating utilities utilizing the extract, transform, and load (ETL) tool developed during the project. The database and tools were created with the direct guidance of an expert committee formed from the utility participants. Python script language was used to develop the data transfer tool, while an ArcGIS server file geodatabase was utilized to run the Web-based map service. The tools were piloted with the utilities and demonstrated a more accurate and informative alternative to current practices. Further, it was deemed to be an excellent method for preliminary budgeting and prioritization for pipeline projects by the participating utilities and expert committee.

This paper describes a modification of the City of Portland's (City) Bureau of Environmental Services's (BES) asset management approach by including a statistical evaluation during design that targets cost-effective solutions for service lateral replacement/rehabilitation. BES has undertaken a large-scale program ($200 million) of combined sewer replacement/rehabilitation for small-diameter sewers located predominately in residential neighborhoods. The program has been managed through BES's asset management plan. Projects have been planned based on highest priority sewers (highest consequence of failure) and condition (risk of failure). Sewers have been video inspected and assessed based on their condition assessment codes and grading system. The City's standard procedures dictated full replacement of all sewer laterals to the curb (the City's jurisdiction) wherever full replacement of the mainline sewer was identified. The basis for justification of sewer lateral replacement was founded on the strategy that if the mainline needed rehabilitation, then the laterals, being of the same vintage, would be defective to a similar degree. This paper will discuss a statistical approach based on video inspections during design and condition assessment of a sampling of laterals from various vintages and locations in several projects. The results of the evaluations, when combined with the established asset management approach revealed that only a small percentage of sewer laterals actually meet the criteria for rehabilitation. The data were used to project cost implications based on a three-tiered plan. A separate programmatic approach was developed to include field validation during construction. This approach provides for inspection by the contractor of all sewer laterals when the mainline has been excavated for replacement. The City's construction inspection staff received training and guidance necessary to make onsite assessment of the laterals and City inspectors were empowered to determine if replacement was necessary. Project pricing included bid items for additional work directed by the City. The first project utilizing this strategy bids January 2014 and will be constructed in mid-2014. Results of the work from a lessons learned review with the contractor and inspection team will be presented and discussed to provide feedback on the programs success and recommendations going forward.

The Regional Municipality of Peel is situated in Southern Ontario about 475 km from Canada's capital, Ottawa. It consists of three municipalities: the Town of Caledon and the Cities of Brampton and Mississauga and is part of the Greater Toronto Area. As the second largest municipality of Ontario, it remains one of the fastest growing regions in Canada with a current population of 1.3 million, projected to be 1.68 million in 2031. With this growth, it is essential that planning and investment of infrastructure keep pace with expected developments.

Broken prestressing wire wraps are the main cause of failure in prestressed concrete cylinder pipe (PCCP) and are typically caused by corrosion, hydrogen embrittlement, overloading, high internal pressures, and manufacturing defects. In a previous study, it was shown that without considering the interaction between two adjacent pipes, broken wire wraps at the joint reduce the strength of a PCCP. In this study, the effect of broken wire wraps on the structural integrity of a damaged PCCP was investigated considering full interaction and perfect bond between the spigot and bell ends of adjacent pipes. The stress and strain in the various components of a damaged PCCP were investigated by increasing the internal pressure of the pipe while varying the number of broken prestressing wire wraps (i.e., manipulating the severity of the damage). The results were calculated for a 96-in. embedded cylinder pipe (ECP) design with 5, 35, 70, and 100 broken wire wraps. Based upon the results obtained, a comparison between the effect of the broken wire wraps in the barrel of the pipe and broken wire wraps at the joint is presented and discussed.

The Hoppers Crossing Pumping Station comprises two wells, each of which contains four pumps. Both wells may be considered as separate hydraulic entities as they are each supplied by separate suction lines from the penstock chamber. Within a well, each pump discharges into a rising main, which rises vertically for 40 m. A pair of rising mains then discharges into a common discharge main that runs horizontally before discharging into the delivery chamber. Each pump can discharge up to 8 m3/sec. An incident during commissioning tests demonstrated the potential for severe transients to occur in the rising mains. The particular incident occurred during rapid pump delivery valve closure on one pump. Investigation of the incident included detailed pressure and flow measurements under gentle transient conditions and the development of a numerical model. The model was verified against the detailed field measurements. The investigation showed that the cause of the incident was column separation in the rising main. No structural modification could be practically introduced to protect the system against column separation. Numerical simulations were then performed that led to the development of valve operating protocols to avoid unacceptable transients. It was shown that unacceptable transients could be avoided, even during rapid total valve closure, if the valve was closed very rapidly over the first 72% and slowly over the final 28% of closure.

This paper presents the key findings of the use of C-factor testing as a condition assessment tool for more than 20 wastewater force mains in terms of existing condition and projected useful life. The efficient and effective operation of sanitary sewer lift and pump stations and force mains is critical in the overall operation of many sanitary districts in the United States. Many times, the actual operation of these hydraulic facilities is very different from the original design intent. C-factor testing is a quick, minimally invasive means of determining the actual flow rate, pressure, and friction loss through the station piping and force main system. If the operation of the system has been changed or the amount of flow has increased or decreased, this may have a dramatic impact on the operation of the facility from an efficiency point of view. This paper presents the results of more than 20 actual field measurements of C factors on existing sanitary sewer system force mains and the findings in terms of pump efficiency, amount of debris in the force mains, and the general operating conditions of the stations. The paper presents how this tool can assist owners in managing their systems for longer operational service lives.

The Metropolitan Water District of Southern California (MWD) is a consortium of 26 cities and water districts that provides drinking water to nearly 19 million people in parts of Los Angeles, Orange, San Diego, Riverside, San Bernardino, and Ventura counties. Metropolitan currently delivers an average of 1.7 billion gallons of water per day. Metropolitan has 830 mi of pipelines, of which 163 mi are prestressed concrete cylinder pipe (PCCP) lines. The lines are distributed throughout Metropolitan's service area in both urban and rural areas. The pipelines range in diameter from 54 to 201 in. and operate at pressures up to 340 psi. Metropolitan's PCCP was constructed between the early 1960s through the mid-1980s. In 2000, Metropolitan initiated its PCCP assessment program. It included inspection of all 163 mi of PCCP lines using electromagnetic and visual inspection methods. Since that date, electromagnetic inspections have been performed annually during the winter shutdown season, with an average of 35 to 40 mi inspected every year. Every year the results of these electromagnetic inspections are reviewed and pipe considered to be at high risk of failure is repaired. A total of 7,534 ft of pipe or 378 pipe segments have been repaired since 1999 at a total cost of approximately $65 million. Metropolitan has recently changed its asset management philosophy of PCCP from an inspection-driven reactive method to a systematic replacement of its most at-risk pipelines. This paper will discuss the first planned systematic replacement of one of its PCCP pipelines—the Second Lower Feeder. The Second Lower Feeder (SLF) has 29 mi of PCCP. The pipeline varies in diameter from 84 in. to 78 in. This paper will discuss the reasons for the change in philosophy of the asset management approach, the technical challenges faced by the project such as loss of hydraulic capacity, the approach to scheduling long shutdowns, prioritization and sequencing of the relining effort, and the various replacement options considered.

Trenchless technology has become an increasingly popular underground utility construction method. Beginning in the early 1900s with jacking beneath railroads, trenchless construction became more common throughout the century and into the current day. The utilization of horizontal directional drilling (HDD) technology is associated with the potential risk for ground subsidence and soil heaving. Sinkholes and settlement can form after construction, damaging existing infrastructure and causing safety hazards. HDD methods require an annular overcut, disturbing soil around the outer diameter of the utility being installed. While the annular overcut is necessary for feeding pipes through the borehole, when used in conjunction with a liquid lubricant, the likelihood for developing voids increases. The annular overcut is also a concern because the consistency and void ratio of the overburden soil change after boring or jacking. Inconsistent and void-ridden soil can cause void propagation through the overlying soil until it reaches the surface, where it will become a sinkhole or crack. This paper addresses postconstruction evaluation methods, especially pertaining to the annular space and void propagation region above and around a freshly installed utility installed by the horizontal directional drilling method in Southern Virginia. Two nondestructive evaluation methods are used to scan the surrounding soil: ground-penetrating radar (GPR) and FutureScan. FutureScan, a radar device developed by Louisiana Tech University, is capable of being attached to pipe inspection robots and uses a means of penetrating radar to detect voids and inconsistencies along the outer utility wall. This study examines the difference between GPR and FutureScan, regarding the imaging techniques used and the measured void ratios. All soil conditions for this study pertain to the Virginia Piedmont region. Relative elevations were recorded before, during, and after drilling to measure surface movement caused by drilling efforts. The relative elevation was also recorded several months after utility installation, so it could be compared at a long-term scale. Long-term results indicate whether or not the imaging techniques imply subsidence or heaving in the long term. After analysis was conducted using GPR and FutureScan, representative soil samples of the test site were retrieved and transported to a geotechnical laboratory for further testing. Based on the GPR and FutureScan findings, the utility of the two postconstruction evaluation methods was determined. The results were compared to the relative elevations recorded in the field. Void ratio field data and equipment reliability are limited to Virginia's Piedmont region.

The ductile iron pipe industry offers a variety of proprietary restrained joint products. (In this paper, the abbreviation PRDIP is used for proprietary restrained ductile iron pipe.) As with any product, optimum performance of PRDIP results when the manufacturer's installation instructions are followed. However, when these instructions are not followed, problems may result. Many miles of pipe were successfully installed for the project presented in this paper. At some vertical diversions, problems occurred where proprietary restrained joints were not fully extended. This paper is a generic investigation of a 36-in. (900 mm) pressure pipeline project, but the information presented in Section 3 is based on an actual installation. One of the problem locations from that project is examined in detail. Vertical diversions in this project were particularly sensitive to the pipeline expansion that occurs if the PRDIP is not fully extended. Most designers and installers are aware of this issue and extend the joints whenever pipeline expansion would harm the pipeline or surrounding structures. Ductile iron pipe manufacturers have recommendations in their product literature for how this may be accomplished. To provide proper context, the paper begins by describing the issue. It then discusses in broad terms how the issue may be easily addressed and eliminated as a concern.

Approximately 2,000 lineal ft of 48-in.- to 72-in.-diameter, unlined carbon steel piping used for cooling water circulation was replaced at Lawrence Energy Center, a 580-megawatt coal-fired power generation facility owned and operated by Westar Energy, during planned outages in spring 2009 and spring 2011. Due to interferences associated with power plant infrastructure above and in close proximity to the piping, sliplining with new carbon steel piping was one of several replacement technologies that were employed. In all, approximately 1,520 lineal ft of sliplining was accomplished during the planned outage timeframes, including a number of elbows and changes in pipe diameter. Sliplining with new carbon steel pipe was found to be a technically sound and cost-effective approach for replacement of existing unlined carbon steel pipe and was especially advantageous given the challenges associated with completing hundreds of lineal ft of pipeline replacement work in somewhat short outage timeframes. With detailed planning, both phases of the construction effort were completed on schedule, safely, and within budget. Keys to the success of the project included the pipeline installation contractor's involvement and ability to innovate early in the project, especially in the conceptual design phase; Westar Energy's implementation of its Outage Readiness Index framework, with partnership in planning between the owner and other project team participants; and extensive collaboration with pipe suppliers prior to fabrication.

In 2013, Tacoma Water completed the robotic application of a semistructural polyurea liner in 2,168 lineal ft of 58-in. ID steel pipe installed in 1936 and repaired numerous times over the years to seal pin-hole leaks. Selection of a spray-applied, semistructural polyurea liner (defined by AWWA Manual M28 as a Class III semistructural liner) for rehabilitation of the pipeline on this project began in 2011 with the development of a business case evaluation (BCE), which compared the life-cycle cost and social/environmental impact of various rehabilitation methods to identify the least expensive and least disruptive option to seal leaks and extend the service life of the pipeline. The BCE included consideration of an option to continue repairing leaks until 2036 when the pipeline would be scheduled for replacement (i.e., the business-as-usual option); complete and immediate replacement of the pipeline with an equal size steel pipe with polyurethane coating and lining; slip-lining with a 54-in. OD HDPE pipe; spray-applied, semistructural polyurea liner; cured-in-place pipe; and cement-mortar lining. Although the Class III liner option was more expensive than the business-as-usual option, it was considerably less expensive than the replacement option and it made less of a social/environmental impact than either the business-as-usual option or replacement option. The other options considered did not meet technical requirements or were more expensive. This paper and presentation will cover the process used to evaluate pipe rehabilitation options and Class III liner pros and cons, polyurea material properties and testing, and application technology; review the performance of the lining application; and present the lessons learned from the first successful large-diameter, potable-water spray-applied, semistructural polyurea liner installation. Attendees at this presentation will acquire new knowledge about the advances in Class III liner design, polyurea material development, and robotic lining technology. Specifications, product literature, and industry partner information will be available for distribution. Spray-applied, semistructural liners created using specially developed polyureas applied with the proper equipment in the right conditions can certainly be considered as a cost-effective and low-impact option for the rehabilitation of large-diameter, potable-water pipelines. This paper and presentation will demonstrate that Tacoma Water is at the forefront of innovation and sustainability.

Winnipeg, Manitoba, is a city in central Canada with a service area population of more than 700,000 people. Cell 1 and 2 of the Deacon Reservoir are critical components of the overall water supply system for the City providing seasonal balancing and emergency storage for the raw water supply system. Under normal operating conditions the two cells have 4.1 billion L of water in them or 47% of the total seasonal balancing and emergency storage in the system. Their maximum operating depth is 8.5 m. Cell No. 1 was constructed in 1972 and Cell No. 2 in 1978. The two cells are interconnected with 1829 mm (6 ft) high and 2,438 mm (8 ft) wide concrete box culverts that are predominately in 1.8 m long precast sections. The interconnector pipes have leaked extensively since their original construction. Considerable effort has been made to repair the original leaks including external soil grouting, channeling excess leakage to an adjacent underdrain system,0 an extensive program of installing hypalon diapers over the joints, and finally polyurethane injection of the joints. While many techniques were successful for a time, all had somewhat short effective design lives. Due to the high risk, cost, and logistical complexity of taking the reservoir cells out of service for rehabilitation work, a more robust long-term solution was desired, and the City wanted to employ mitigative alternatives that would have a considerably longer design life. Further, as emergency storage is a critical component of maintaining reliability of supply, the City desired a solution that could be implemented with the reservoirs in full service. After reviewing all established relining and rehabilitation technologies, the preferred option was to slipline the culverts with circular 1,600 mm DR 26 HDPE pipe. This is the largest solid wall HDPE pipe that can be extruded in North America. To complete the installation at full reservoir head required considerable innovation. The HDPE liner pipes were fused and tested on shore prior to being floated into position, sunk, and pulled into the culverts. To facilitate blocking the liner in place and the grouting of the large annulus in a controlled environment, a mechanical bulkhead utilizing pneumatic seals was designed and installed within the existing box culvert to facilitate dewatering each culvert without affecting the reservoir levels. While working under full reservoir head, concrete bulkheads were installed at each end of the lined section and the annulus between the existing box culvert and the HDPE liner was grouted with a very carefully designed and monitored controlled low strength, low density material (ACI 229-R2). The project was successfully completed in 2012/2013. The paper will provide an overview of the design and innovative construction process and the quality assurance procedures employed to confirm that the finished construction product met the design intent. Initial postinstallation monitoring results will also be presented.

The Southern Delivery System (SDS) is a regional project to bring water from the Arkansas River to Colorado Springs, the City of Fountain, the Security Water District, and the Pueblo West Metropolitan District. Phase 1 of this two-phase project includes all of the components necessary to begin delivering water to the partner communities by April 2016. SDS Phase 1 construction commenced in 2010 with water delivery expected by April 2016. Core components include a reservoir connection at the North Outlet Works of Pueblo Dam, approximately 50 mi of predominately 66-in. diameter raw and treated water pipelines, three pump stations with a total of 26,750 horsepower, and a 50 million-gallons-per-day (mgd) water treatment plant and finished water pump station. Construction, commissioning, startup, and the ultimate operation of any large-scale water supply system, such as the SDS, warrants careful and thoughtful water planning. The SDS pipeline will require approximately 63 million gallons of water just for testing and initial filling. Conserving this valuable commodity is a key element to the successful implementation of the SDS. Throughout development of the SDS project, significant volumes of water are needed for construction to support activities such as dust control, earthwork compaction, hydrostatic testing of multiple pipeline sections, and operational needs ranging from initial filling of the system-wide pipeline and related facilities to long-term maintenance activities. To better manage and conserve the use of water for these purposes, MWH and Colorado Spring Utilities collaborated to develop a unique water management analytical tool. The SDS Water Management Tool evaluates and tracks water quantities needed to support filling, draining, and transferring water from one constructed pipeline section to another and manage water during planned maintenance activities such as filling, air management, operational head, operational flows, draining/dewatering, release and treatment of discharges, permit tracking, and reporting. Additionally, the SDS Water Management Tool will be linked to the SDS electronic operations and maintenance manual to assist operations staff in making operational decisions for the future. This paper provides background on the development, calibration, and implementation of the SDS Water Management Tool and describes the techniques used for sound management of construction and operational water for the SDS project.

The ability of a water distribution system to deliver sufficient fire flow is gaining greater attention as Peel Region is trying to maintain sustainable growth in the system. As requested by the fire department, Peel needs to color code every hydrant in the system in accordance with standard NFPA 291. The color coding of about 30,000 hydrants based on maximum allowable water supply would be an extremely challenging undertaking for the Region so it has decided to leverage its hydraulic model to help identify the system's capability in delivering fire flow for all hydrants. With the calibrated model, the maximum available fire flow while maintaining a minimum system pressure of 20 psi can be estimated for every pipe. The results were reviewed with the Region's operation staff to confirm the results accuracy and identify any potential system deficiencies, data gaps and water replacement requirements for the Region. From our presentation, the attendees will learn the following importance of aspects of the fire flow analysis. (1) System upgrades to improve system redundancy and water system security. (2) Reprioritization of the "state of good repair."(3) An effective way to physically color code 30,000 hydrants in the system.

Corrosion, a leading cause of failure in metallic transmission pipelines, significantly affects the reliability and safety of metallic pipelines. To assess and monitor pipeline corrosion and provide substantial information to locate corrosion induced pipeline damage, this study proposes an optical fiber sensor based on long-period fiber gratings (LPFGs) for a corrosion-induced deterioration assessment of pipeline structures. A thin layer of nano iron/silica particles dispersed polyurethane is proposed to be coated on the outer surface of the LPFGs. With the thin metal dispersed layer over an LPFG, both its resonant wavelength and intensity of the resonant peak are altered. Accelerated laboratory corrosion tests are implemented to validate the feasibility of the proposed sensing system. Test results showed that within the detection limitation of the thin coated layer, the proposed sensor could monitor both the initial and stable corrosion rate consistently. With multiple LPFGs in a single fiber, it is possible to provide a cost-effective corrosion-monitoring technique for pipeline corrosion monitoring.

Tacoma Water is a public water utility serving approximately 300,000 people in Tacoma, Washington, and neighboring communities. Founded in 1893, Tacoma Water owns and operates more than 1,200 mi of distribution water mains with more than 95,000 service connections. Like many water utilities, Tacoma Water faces the challenge of a limited capital budget and aging infrastructure. To compound this challenge, Tacoma Water has acquired multiple smaller water systems beyond its original borders with little known service history, making their useful life more difficult to assess. As a means of bridging the gap between available capital funds and the capital requirements of replacing aging mains, Tacoma Water has conducted two pipeline condition assessment projects to ensure that these limited capital funds are spent where they are most needed. In 2011 and 2013, Tacoma Water assessed 19 and 12 miles of distribution mains using an acoustic method for measuring the average remaining structural wall thickness of water mains. This method is fully nondisruptive, requiring no insertion of sensors into the mains, and no interruption of service for customers. These results were used to calculate the remaining useful life of each of the mains, which guided the prioritization of main replacement projects. This paper provides details of the Tacoma Water condition assessment projects, the technology used, the benefits of performing condition assessment, and how this has shaped the pipe replacement decision process in Tacoma Water.

The Green Bay Water Utility (GBWU) proactively conducted an electromagnetic inspection in 2010 of three 36 in. diameter water transmission mains (about 25 mi total length) that deliver water between the water treatment plant and the distribution system. The pipelines were installed in 1953, 1965, 1969, and 1974 so the pipe was manufactured according to different AWWA standards. In December 2012, a pipe failure occurred on the 1974 pipeline. The repair identified the pipe that failed as one that was identified in the inspection as having broken wires but was not determined to be at a high risk of failure. The GBWU recognized the need to identify the cause of failure by conducting a forensic evaluation. GBWU also understood the criticality of these pipelines and the need to develop a plan for managing the maintenance of these pipelines based on a risk analysis. The team of Black & Veatch and Simpson Gumpertz and Heger (SGH) was selected to conduct a forensic evaluation and determine the action plan for the maintenance of these pipelines for the utility to minimize the risk of failure of the pipelines. Our investigation included inspection of the failed pipe, petrographic analysis and testing of mortar coating, testing of prestressing wires and steel cylinder, soil corrosivity testing, and structural and failure risk analysis for pipes with broken wires. To assess the risk of failure of other pipes in the line, we performed external inspection and testing of a sample of pipes and evaluation of alignment soil and ground water corrosivity. The Green Bay Water Utility (GBWU) provides water to the City of Green Bay and surrounding communities. The water treatment plant is located east of the city, and the water is conveyed by gravity about 11 mi to the system at the John's Street Pressure Reducing station and vault through two 36-in. transmission mains. These mains are parallel and constructed at different times. The 1953 Lake Michigan Water Supply Line was constructed of PCCP manufactured by Lock Joint Pipe Company. The 1965 transmission main was manufactured by International Pipe and Ceramics Corp, a Lock Joint Company and constructed to Alpine Road. Then in 1974 the C74 Transmission and Feeder Main project extended the pipeline to John's Street station. The 1974 pipe and segments of the 1953 pipeline replaced to relocate the pipe for a road construction project were manufactured by Interpace Corporation. In 1969 a 36-in. pipeline was extended north on Grandview Road. This pipe was manufactured by Interpace Corporation. The system is operated using the elevation difference between the reservoirs at the treatment plant site and the distribution system to provide the operating pressure for delivery of the water to the customers. The system includes several pressure regulating stations off the transmission mains to monitor and control the pressure to the distribution system. In October 2010, Pure/PPIC completed an inspection of three 36-in. pipelines using the remote field transformer coupling (RFTC) technology on the pipe diver platform. The inspection was performed on the 36-in. 1953 Lake Michigan Water Supply line, the 36-in. 1965 C74 Transmission and Feeder Main, and the 36-in. UWGB Transmission Main Pipeline. The results of this inspection determined that 20 pipe segments out of the 8,141 segments inspected displayed evidence of wire breaks ranging from an estimated 5 to 15 broken wires. On December 29, 2012, a failure occurred on the pipeline installed in 1974 at the location of one of the pipes identified in the Pure/PPIC inspection report. The leak occurred on East Mason at Skyline Drive. When the C74 pipeline failed, the SCADA system alarmed at 7:15 a.m. with low inlet and outlet pressures at Grandview (5 psi), John Street low pressure, and wells 2 slow pressure. The leak was identified on the "north (C74)" line, and the pipeline valves were closed by 10:30 a.m. The pipe section that failed was at station 66+24 and corresponds to pipe segment 2420, with 10 broken wires, 2.5 ft from the joint in the Pure/PPIC report.

On July 1, 2013, a wildfire was started by a lightning strike in the Spring Mountains, located west of Las Vegas, Nevada. Two small water systems were affected by the fire, Trout Canyon and Kyle Canyon. The fire burned more than 27,800 acres and by July 15, 2013 the fire was 70% contained, allowing the evacuated residents to return to their homes. The fire was not 100% contained until September 17, 2013. The NvWARN system was activated to repair the Trout Canyon Water System utilizing materials from water systems throughout Nevada and crews from the Las Vegas Valley Water District. Repairs, from the fire damage, on the Trout Canyon Water System were completed on August 30, 2013. Heavy rains over the Labor Day weekend, dating from August 30, 2013 to September 2, 2013, caused massive debris flows that completely destroyed the Trout Canyon Water System and damaged the Kyle Canyon Water System. This paper describes the damage that occurred to both the water systems and shows more damage to water systems can occur after a forest fire than during the actual fire event. This paper also discusses how emergency agreements that are in place will assist smaller communities, but the smaller communities still need emergency plans and funding sources before a disaster occurs. Finally, the paper contrasts the damage to an upgraded modern water system versus an older system, showing how the modern system withstood the storm with less damage.

The City of Glendale (City) operates the Arrowhead Effluent Reclaimed Distribution System (AERDS) Pipeline to convey reclaimed water from the City's Arrowhead Ranch Water Reclamation Facility (ARWRF) to various irrigation facilities and lakes within the Arrowhead Ranch development. The pipeline was constructed in 1987 and consists of 24,225 feet of bar-wrapped, thin steel cylinder covered internally and externally with cement mortar and includes 8,330 ft of 36-in., 3,110 ft of 30-in., 2,770 ft of 24-in., and 10,015 ft of 16-in. diameter pipe. The City experienced three localized failures on the pipeline in 1998 and 1999 after construction of the SR 101 near the pipeline alignment but has not experienced subsequent failures. To determine the pipeline condition after 25 years of service, the City initiated a pipeline assessment in 2013. Because the AERDS pipeline is critical to operation of the ARWRF (an end-of-the-line facility) and cannot be out of service, an innoviative step-wise approach was implemented utilizing appropriate technologies and modifications to operations to maintain flow. Information from each step was used to identify the next step inspections. This cost-effective approach has saved the City more than $400,000 and allowed the work to be completed without operations interruption. This paper will describe the challenges faced to keep the pipeline in service during the inspection by using indirect corrosion potential testing and a combined leak detection and video platform. To provide coverage for a critical portion of the pipeline under the highway the pipe was hot tapped for insertion of the inspection tool. The results of the interior assessments combined with indirect soil testing and sampling identified the areas for excavation and exterior testing. The nondestructive evaluation inspection of the pipe exterior with the impact echo and slab impulse technologies provided information on the condition of the pipe. This step-wise approach shows how the condition assessment can be completed with the pipe in service.

When a surge tank system in operation since 1990 on the 48-in. ductile iron finished water transmission main coming from the Atlanta-Fulton County Water Treatment Plant (AFCWTP) began to fail in 2010, the City of Atlanta's Department of Watershed Management (DWM) initially looked at a steep repair bill to restore the system. The surge system consisted of two 20,000 gallon underground tanks located in a physically restricted commercial parcel in the town of Johns Creek, both connected via a 36-in. steel surge line to the City's transmission main. The surge tanks were taken off line in 2010 due to apparent leaks and subsequent repairs needed at the tanks and pipe connecting the tanks to the main. The cause of these leaks spurred an investigation by the DWM and Jacobs's staff in January 2011 that concluded in May 2012 and included these major activities: (1) physical inspection of the two surge tanks and the connecting surge line with the assistance of a pipeline contractor who had excavated down adjacent to one of the tanks and a portion of the steel line; (2) recommendations on rehabilitating the tanks to put them back into service and further investigation and possible rehab options on the surge line, which included short-term additional cathodic protection measures to arrest deterioration of the steel pipe; and (3) transient analysis of the Atlanta main from the AFCWTP through to the connection to the City's distribution system south of the suburban city of Sandy Springs near the low point at the Chattahoochee River. The final activity, the transient analysis of the main, was done to determine if the surge tanks at the Johns Creek location were needed and should therefore be rehabilitated along with the surge line based on how the system was configured and being operated. Approximately $500,000 went into excavating the facilities there, doing the investigation, cathodic protection, and restoration of the site, and the City wanted to ascertain the need to make further investment in those facilities. The transient analysis was revealing in that other operational and maintenance items, like sizes, locations, and operability of air release valves (ARVs) and interconnects with adjoining systems could have as much impact on protecting the transmission assets as the operation of the surge tanks.

Asset management targets the sustainability of civil infrastructure throughout combining engineering and economic principles to meet customers' needs and avoid likely catastrophic failures. In the past decade, researchers commonly focused on developing techniques for understanding and controlling the performance of isolated infrastructure networks by using various simulations and statistical and optimization techniques. However, the developed models overlooked the spatial and functional interdependencies between various civil infrastructure. For instance, consider failure in a water main, the structural and functional capacity of the spatially interdependent road may likely be compromised thus affecting other surrounding roads' functionality. This raises the call for developing integrated asset management tools for identifying interdependent assets and capturing to which extent one asset failure can affect neighboring assets' performance. This paper provides a framework for capturing spatially and functionally interdependent assets that consists of two models: 1) a spatial interdependency model and 2) a functional interdependency model. The spatial interdependency model utilizes ArcGIS geoprocessing tools in determining geographically interdependent assets. The spatial interdependency model encapsulates the interdependent assets in a set of new layers and a new generated database containing characteristics of such interdependencies. However, the functional interdependency model employs graph theory principles in determining an asset's degree of connectivity with its neighboring assets. The functional model will aid in recognizing the likely influence of an asset failure on its neighboring assets' performance using two proposed parameters: 1) neighborhood centrality and 2) significant point variance. A case study using City of London water and road network will be used to demonstrate the potential for applying the proposed framework.

Sulfur oxidizing bacteria (SOB) have been found to be important promoters of concrete biodeterioration. Some microorganisms such as Halothiobacillus neapolitanus, Thiobacillus thioparus, and Acidithiobacillus thiooxidans have been associated with important weight losses in concrete structures exposed to humid and aerated environments with low to high concentrations of hydrogen sulfide and carbon dioxide. Particularly sewers and some underground structures can be exposed to these aggressive conditions and suffer an accelerated deterioration. In this paper we present the results of a set of experiments using mortar samples with high surface-to-volume ratio inoculated with SOB and exposed up to 200 ppm H2S in nonaseptic conditions. The results showed significant changes in mechanical properties such as weight, strength, and porosity in less than six months. Particularly observed weight losses are larger than those reported by previous studies in the same time span suggesting that the highly exposed surface-to-volume ratio used here is a predominant factor for the biodeterioration rate.

Strengthening of pressure pipelines using carbon fiber-reinforced polymer (CFRP) materials has been an accepted repair method since the late 1990s. CFRP composites are high strength, noncorrosive, and durable materials and can add considerable structural capacity, which makes them very suitable for pressure pipeline strengthening. However, there are several keys to success and best practices with regard to material selection, design, construction, and quality control. There are lessons learned through installations that have taken place over the past 15 years. These include adoption of criteria for material selection, new design philosophies, termination end detailing, and critical points during the construction process. This paper provides state-of-the-art information regarding materials, design considerations, installer experiences, and current best practices. Field case studies provide a comprehensive review of the use of CFRP composites.

Most people give little consideration to the upkeep of a pipe network once it is put into place. After all, operation and maintenance should be regimented, straightforward, and based on common sense. Do we really need a management plan for common sense? Well, the answer is yes. In fact, you need a good one. The durability and longevity of the piped assets, coupled with their "out-of-sight" nature, leads many to forget their importance until a rupture occurs or a road has to be closed. When pumps and motors fail after only a few years and require constant service, it is easy to see how a pipe asset that measures service in decades can be overlooked. However, when Gwinnett County began looking at its pipes, we found that the operation and maintenance of these critical assets was not so easily defined nor were many of the assets as durable as we had originally thought. Gravity systems are not always self-cleaning, and pressurized pipes do not always work efficiently just because we tend to the pumps. The pipe networks in our system have a value equivalent to the vertical assets, and, though they should survive multiple replacements of those mechanical components, they cannot be overlooked either financially or operationally.

A sudden break of a pressurized and dead-ended water main induces water hammer and possibly column separation at the dead end. Because a line break is an energy venting and depressurizing event, one may not anticipate overpressures as a result of the break. The purpose of this paper is to show that a line break can generate excessive overpressures severe enough to cause damage. Through analysis and laboratory tests, we demonstrate that (1) if column separation does not occur at the dead end of the main line, the transient pressure in the main does not exceed the initial pressure in the main prior to the break; (2) if column separation occurs, the transient pressure in the main can exceed the initial pressure; and (3) damaging overpressure in the connected service lines may occur whether column separation occurs in the main or not.

The Blue Plains Advanced Wastewater Treatment Plant owned by District of Columbia Water and Sewer Authority (DC Water) is one of the largest wastewater treatment plants in the world. One particularly critical pipe within the facility is the Nitrification RAS Line, which transports sludge and is located in underground galleries. Through inspection it was identified that eight elbow sections of the 84-in. steel pipeline had significant thinning and were in need of repair during the scheduled 2013 pipeline shutdowns. Four 90-degree elbows and four 45-degree elbows required a structural upgrade, and CFRP was selected as the appropriate structural lining system based on DC Water's previous successful history with this material. The EPA regulates the amount of time this facility can be shut down and dictates that only half the piping can be shut down at one time, so the cleaning, inspection, weld repairs, CFRP and topcoat installation, along with full cure of the repair system had to take place over the course of two five-day shutdown windows. This paper will provide details and owner feedback on the design and construction process undertaken for this unique project.

Obtaining adequate cathodic protection can be challenging on a campus where there are several mixed-product use pipelines. This is a case study of more than 10 years' experience on a campus that has potable water, high-pressure air, natural gas, and other water pipelines. The pipelines are electrically continuous in several locations. Methods that were used to test the cathodic protection system are presented. Issues with maintaining compliance with CFR Title 49 Part 192 regulations for monitoring cathodic protection systems are addressed. Corrective action measures that were implemented to maintain protection are explained.

A critical 30-in. prestressed concrete cylinder pipe (PCCP) potable water transmission main in the Atlanta water system, the primary feed for a major repump station, was leaking. Total pipe failure had not yet occurred, but surface water and saturated ground indicated that a leak was potentially affecting an adjacent bridge foundation. Neither the exact cause of the leak nor the as-built conditions of the pipeline or bridge were initially known. Operations staff advised that once repairs were started they must be completed within a 12-hour window, or a large customer base would be out of water service. A team of City workers accepted this challenge but would eventually face and resolve several issues that will change the way future transmission mains will be repaired in Atlanta, GA. Preplanning was essential, but didn't prevent some surprises. The leak occurred at a PCCP to steel pipe interface at the transition through a bridge abutment and near a major thrust block for a vertical bend. Draining the pipe, dechlorinating the water, and isolating old valves required a much longer implementation time than expected. The initial repair fittings didn't seal and as a result, operations began running out of water at the repump station tanks and pressure began to drop systemwide. A cooperative response team of operations, maintenance, and engineering staff quickly used the City's hydraulic model, distribution SCADA, and GIS to look for ways to reinforce the system. As a result, several options were identified. Adjacent pressure zones were connected, pump station output pressures were increased, and many distribution valve positions were altered to maintain minimum pressure requirements within the system. In several key sections, pressure zone interconnection infrastructure was not available, so temporary creative solutions involving the fire department were implemented. In the end, repairs were completed and customers saw little impact to their daily service and with no regulatory violations. Although the City had been investing in the technical tools to achieve this successful result, these tools had not yet been utilized in an emergency situation to this extent, allowing the team to achieve what no one had seen performed prior to this. In an old piping system, surprises happen. The tools now available for asset management, documentation, and analysis;quality pipe materials; and a motivated, qualified team can make what used to be impossible become a success story of the present.

In the design of water pipe systems, bolted flange joints are usually given minor consideration. Flanges have been successfully used in various types of pipe materials for more than 100 years, and their forms have been standardized for more than 50 years. Most flange joint installations are completed without problem or concern, but when a complication arises, it can rapidly become a major issue for everyone involved. Most anomalies that arise during the service life of a flange joint are rarely due to erroneous design; they are almost always related to poor installation practices. This paper discusses installation issues that may occur with steel water pipe flanges, manufactured to AWWA C207 standards. Topics such as proper bolt and gasket selection, flange face arrangements, alignment during installation, bolt-up patterns, and the relationship between applied bolt torque and achieved gasket stress are discussed, and practical recommendations are provided to avoid some of the common installation pitfalls. A comprehensive list of resources for the practitioner is provided, along with a discussion of recent updates in various flange standards and guides. Water system owners, design engineers, and installation contractors alike will benefit from the contents of this paper as a resource to achieve leak-free bolted connections on future projects.

The topics of liability and negligence as they relate to water main failures are discussed from both a historical and current viewpoint. The historical perspective is provided in a 1948 Journal AWWA article, and we consider changes in liability issues from that time to the present. Case studies from various states are also presented that will provide water utilities insights into sovereign immunity and what constitutes discretionary function. Some of the key findings for water utilities were that they should understand the laws and relevant legal decisions in their state because each state has its own laws related to how immunity is determined; that even immunity, in some states and or cases, may not be the final determining factor that can relieve them from liability for breaks and leaks; that they should implement a written policy or plan to address deteriorating infrastructure; and that they should keep accurate and comprehensive records.

The City of Baltimore (City) operates 4,000 mi of water infrastructure. With an average age of about 80 years, the aging infrastructure is showing signs of deterioration in terms of water main line breaks. Baltimore is currently implementing an aggressive water infrastructure renewal program (the Program) to replace the aging water distribution system. The program intends to replace or rehabilitate the water distribution system using a systematic, prioritized approach that considers both the condition and the criticality of the assets. Condition refers to the likelihood of failure, while criticality denotes the consequence of failure. The condition considers factors such as customer complaints, leakage history, pipe material, and age. Criticality factors include major customers such as hospitals, pipe sizes, and system pressures. To date Baltimore has about 15 projects under construction or design that will deliver approximately 15 mi of pipe replacement in fiscal year 2014. Moreover, close to 20 additional projects are under design that will deliver 30 additional mi scheduled for construction in fiscal year 2015. Furthermore, the City has engaged additional design teams. These additional teams will deliver about 70 mi of design, allowing Baltimore to replace 35 to 40 mi of pipe in fiscal year 2016 and beyond. Managing the design teams and an aggressive construction program requires careful planning, a dedicated trained staff, a disciplined and standard approach, and an extensive community outreach program. The paper will explain to the audience how each phase of the program was planned and executed, starting with the development of the condition-criticality model, followed by important consideration in the selection of project areas. Design standards and program management best practices were implemented, followed by construction management practices that made the program a success.

Cement mortar, used as a lining on the interior wall of metallic pipe, has proven to be beneficial in the passivation of metal corrosion in the presence of water. For many owners/agencies the use of cement mortar lining has become a standard when ductile iron or steel pipe is specified. The lining is traditionally applied with a minimum thickness of 0.25 in. by centrifugally casting the cement to the interior wall or, in larger diameters and at joints, field applied. The lining's performance in operation has proven its benefit over time. However, in large-diameter systems that have been in the presence of persistent hydrodynamic loads there have been recorded failures of cement mortar lining. The failure of the cement mortar lining leaves the pipeline exposed to corrosion and potentially exacerbates the problem. In larger-diameter pipelines with aggressive water, it has become common to specify thicker cement lining (>0.25 in.). The concept of the greater lining thickness is to allow erosion of the lining to occur over time while remaining lining continues to passivate the corrosive environment. This is intended to result in an extension of the pipeline's service life. This paper summarizes the development of an analytical approach to evaluate the sensitivity of cement mortar lining in the presence of hydrodynamic (i.e., hydraulic transient) loads. The equation represented in the paper allows a designer to assess the thickness of the lining and the potential of the lining to fail in the presence of a differential pressure caused by a downsurge or negative transient pressure condition. This analytical approach will help refine the evaluation of using a thicker cement mortar lining in lieu of treating the aggressive fluid, assess the sensitivity of the thicker lining in the presence of dynamic loading, identify what transient controls may be required if thicker linings are specified, and better define the extension or potential reduction of a system's operating life through the use of a thicker cement mortar lining.

This paper presents the testing part of a research project for the Water Environment Research Foundation (WERF) to investigate the structural capabilities of no-dig manhole rehabilitation materials to develop a decision-support tool. The project tasks included literature search; industry expert workshop with participating utilities, manufacturers, and other consultants; experiments on structural properties of select manhole rehabilitation materials; and computational analysis with the finite element method. Gravity flow wastewater collection systems essentially comprise sewer pipes and manholes. Failure of a manhole may have catastrophic consequences such as developing a sinkhole in the street and roadway, and at the minimum, wastewater flow will be blocked and upstream of the manhole will backup causing a sanitary sewer overflow (SSO). Improving structural conditions of a manhole is critical to minimize these types of failures. This research considers the impact of several lining materials including cement mortar, epoxy, polyurethane, cured-in-place composites, and a multilayer material on increasing the structural capabilities of deteriorated manholes. Several preliminary tests according to ASTM C-39 on coated concrete cylinders and ASTM C-293 on coated concrete beams were performed at UT Arlington's Center for Underground Infrastructure and Research and Education (CUIRE) Laboratory. These test results showed significant increase in the performance of concrete samples under compression and flexure. A second round of testing was performed on 4-ft long, 24-in. diameter concrete pipe sections with 3-in. thick wall manufactured according to ASTM C-76. These pipe sections were lined internally with the same materials as the preliminary tests and tested according to ASTM C-497 under standard three-edge-bearing test. Using computer data acquisition system, strain gauges, and extensometers, strains and deflections were measured and stresses calculated. The results show that lining materials tested in this study can significantly improve structural performance of deteriorated manholes.

Wastewater pipeline infrastructures are critical for cities, counties, and transportation facilities to enhance drainage during rain storms and minimize local flooding. Infiltration due to leaking pipes and other components of a waste water system will add to the problem of overflow and also overload the treatment facilities. Also frequent overflows not only lead to regulatory problems but increase the treatment cost. Leaking systems will cause erosion of soils through the leaking joints leading to the settlement of the ground surface, formation of sinkholes, and damage to surrounding pavements and structures. Because the ASTM pipe-joint tests varied with the type and size of pipes, a unified test protocol was developed by CIGMAT and approved by a steering committee with representation from the USEPA, pipe associations, cities, and consulting engineers. The testing protocol included the procedures to determine the leakage rates at the pipe joints under shear loading and angular deflection. Using this protocol both rigid (clay, concrete, and fiber glass) and flexible pipes (polypropylene, PVC) with 30-in. diameter (76.2 mm) have been tested in the CIGMAT laboratory. The joints were tested to an infiltration hydrostatic pressure of 50 kPa (7 psi). Pipe joints were tested in duplicate. Relationships between shear load, deflection of the pipe, and the angle of rotation of the pipes at the joint with the applied hydrostatic water pressure at the joint have been developed for various types of pipes tested under this program.

A national survey was conducted during the years 2008-09 by the Center for Innovative Grouting Materials and Technology (CIGMAT) at the University of Houston in collaboration with the City of Houston to document the conditions of small-diameter (< 500 mm diameter) water pipelines in the United States and Canada. Several major cities and few smaller cities participated in the survey, representing a population of 11 million and a water pipeline length of more than 28,000 mi with pipe diameters less than 500 mm. The survey results were analyzed with number of local parameters to establish the general trends observed in the water pipeline failures. The results were also compared with the one conducted by the U.S. Mayor in 2007. The survey conducted by U.S. Mayor included more than 290 cities, representing a population of more than 30 million with water pipeline length of more than 100,000 mi. By comparing the two surveys, the CIGMAT survey represented somewhat larger water systems with several cities having total water pipeline length greater than 1,000 mi. Based on both surveys, the water pipeline breaks per day varied from 0.002 to 12. From the CIGMAT survey, it was possible to investigate the relationship between water pipeline breaks or breaks per mile with numbers of independent variables and the total pipe length in a city was an important parameter. In this study, few relationships were developed for water pipeline breaks using the CIGMAT survey data and the predictions were compared with the USCM survey data.

The East Bay Municipal Utility District (EBMUD) is major water utility providing water to more than 1.3 million people on the eastern side of the San Francisco Bay Area. The EBMUD has approximately 4,200 mi of treated water distribution and transmission pipelines within a 331 sq mi customer service area. Approximately 360 mi of this system are large-diameter pipelines consisting of 20 in. and larger welded steel pipe, 36-in. and larger reinforced concrete cylinder pipe, 16-in. and larger diameter cast-iron pipe, and 20-in and larger pretensioned concrete cylinder pipe. System data are managed using a comprehensive geographic information system (GIS) geodatabase of pipeline characteristics, location, and seismic hazard. Due to the proximity to active faults such as the Hayward Fault, Calaveras Fault, San Andreas Fault, and Concord Fault, the EBMUD service area is very susceptible to earthquakes. Previous studies have suggested that water pipelines are damaged during earthquakes when settlements impose high stresses on the pipeline and its components. Permanent ground deformation is estimated from seismic hazards such as a landslide, fault offset, or liquefaction-induced settlements. A service area that represents this scenario is the City of Alameda, where soil is highly liquefiable in the event of an earthquake. The geology of the city is compromised predominantly by artificial fill and Holocene alluvial fan deposits, with the artificial fill being the most vulnerable to liquefaction. Using 212 cone penetration tests (CPT) soundings located throughout the City of Alameda and geographic information systems (GIS), a pipeline fragility study is performed to determine pipeline segments that have the potential for failure or some level of damage during an earthquake event. In addition, a pipeline map similar to the United States Geologic Survey (USGS) ShakeMap will be created to identify damaged pipeline segments and their corresponding level of damage. After identifying pipeline segments with potential for failure, a repair program is outlined by the authors. The researchers generate the prediction model for the pipeline fragility study for the EBMUD service area, the City of Alameda, based on settlement values obtained by peak ground acceleration values (PGA) and a M7.0 earthquake magnitude. Estimated liquefaction-induced settlement values are verified using the program software SHAKE2000.

Replacing 3.5 mi of 48-in. wastewater pressure pipeline within a densely developed urban public corridor has several challenges. Not least of which is the potential impact from concerns and complaints raised by the public after construction starts. A large regional wastewater treatment utility has completed (January 2014) a successful construction project by providing continuous coordination with the small independent City hosting the pipeline. This utility also simultaneously managed public complaints, quickly addressed unforeseen utilities that were encountered, and managed the permitting and treatment of construction dewatering discharges. A successful urban pipeline replacement project will depend on the strategies prepared for addressing these key project elements. The purpose of this paper is to convey the significant elements of the project and highlight the importance of each element as it pertains to a successful urban pipe replacement project. Key design decisions, effective coordination with the local City, and anticipation of public concerns will all be explained.

Colorado Springs Utilities (Springs Utilities) currently owns, operates, and maintains 1,960 mi of potable water mains. Although many of these pipes have reached or will reach the end of their useful lives in the near future, Springs Utilities is only replacing 0.3% of the potable water system on an annual basis. At this current rate of replacement it will take nearly 80 years to replace the pipe that has already experienced considerable failure and in the next 10 years, pipes are projected to be leaking, breaking, and catastrophically failing in record numbers. Because of these predictions, Springs Utilities hired a consultant to analyze its data and recommend improvements to managing the assessment and replacement of water mains. The consultant's work helped Springs Utilities understand and target key factors that drive failures, making the organization much better prepared to impede the escalating failure rate, predict catastrophic failures, and optimally prioritize water main replacement.

Info-gap decision theory, a tool for evaluating severe uncertainty, can be of tremendous value for managing risk and assessing the vulnerability of water conveyance systems in areas of high seismicity. In those areas, significant consequences can result from decisions made with a profound lack of information, such as the uncertainty of seismic loading, unknown performance of pipelines and other infrastructure, unknown costs to repair seismic damage, and unknown societal impacts from downtime following an event. Info-gap is a tool for making good decisions with very little information and recognizes up front that our best projections of the future may be wrong. Thus, rather than seeking a solution that is optimal for that projection, info-gap seeks a solution that works reasonably well for all plausible conditions. In other words, info-gap seeks solutions that are robust in the face of uncertainty. EBMUD is currently using info-gap to gain insight into possible solutions for providing reliable water service to an island community within its service area. The island, containing about 75,000 customers, is particularly vulnerable to water supply disruption from earthquakes, because it has no water storage on the island and is entirely dependent on four potentially fragile water transmission mains under the waterway for its day-to-day water supply. Info-gap analysis is being used to evaluate competing tunneling strategies for supplying water to the island. Horizontal directional drilling and microtunneling alternatives are being evaluated for their ability to survive a major earthquake and for speed of repair should they be damaged by an earthquake. The analysis considers not only the expected results for each alternative but also the worst-case performance of each alternative under varying levels of uncertainty. Thus, the info-gap model is a tool for evaluating the level of reliability each mitigation buys, even in the face of significant uncertainty. This analysis is improving the quality of the planning process, because it can identify strategies that ensure minimal disruption of water supply following a major earthquake, even if the earthquake and resulting damage fail to conform to our expectations. The model results prompt discussion regarding how much mitigation is desired, or expected to be reliable enough, even in the face of great uncertainty regarding the damage. Results of the study are presented, including a discussion of how info-gap model results complemented existing tools for comparing alternative strategies and how info-gap improves our ability to quantify our tolerance for uncertainty.

Hierarchical decision modeling (HDM) has been developed as a decision-making tool across multiple industries in a wide variety of applications. This paper presents the development of HDM as a tool to be used as an asset prioritization method in the municipal wastewater industry while providing a manual for other agencies to develop a model customized to their particular systems' needs and capabilities. By converting a rudimentary risk-impact matrix, integrating expert feedback across two teams and a manager, and following the guidance of the established problem statement, an effective asset prioritization tool was developed as a means to accurately and consistently score and rank assets according to their priority for consideration for repair or replacement. Following development, a simulation was performed to validate the effectiveness of the tool by comparing it against the experience and expertise of the current decision maker.

All projects are subject to risks that have both a direct and indirect effect on the project cost and time. The risks vary from project to project because of the unique nature of each project. It is important for the project management team to include risk management as an integral part of their project planning and execution. Risk management strategies should be incorporated in every phase of an HDD project to ensure that the project meets the required quality and safety standards and that the project delivery is within cost and schedule. This paper takes a look at horizontal directional drilling (HDD) construction risks (the risks that occur during the construction phase) from the contractor's point of view. Through a literature survey and content analysis of previous works, various HDD construction risks were identified. An industry survey was administered and interviews with major HDD contractors in the state of Ohio were conducted and both the probability of occurrence and impact of these risks on project cost were determined. The paper employed the use of a probability-impact model to identify the critical construction risks and suggests risk management measures and strategies that can be utilized to effectively minimize the risks.

The 1906 San Francisco earthquake (magnitude 7.8) is considered to be one of the most severe earthquakes in U.S. history. Approximately 80% of San Francisco's (City's) total loss was caused by the fires following the earthquake. The earthquake and resulting fires caused approximately 3,000 deaths and destroyed nearly 28,000 buildings. The domestic water system was severely damaged, sustaining more than 300 breaks on water mains and 23,000 breaks on service connections. There was virtually no water available for firefighting. A study was conducted in 1908 to evaluate the need for a dedicated water system for firefighting in the City. Construction of an independent fire protection system, known as the Auxiliary Water Supply System (AWSS), was implemented to be used as the secondary defense against fires in the event the potable water system fails. This paper describes the process to select and recommend a preferred program alternative that optimizes benefits from repairs and improvements to the AWSS, given the potential for seismic activity in the area. Level of service (LOS) performance goals were targets selected by San Francisco Public Utilities Commission (SFPUC) decision makers against LOS criteria metrics by which performance of the AWSS and the benefits of the improvement program (Program) were measured. Performance of the AWSS with regard to the LOS criteria was measured using various modeling tools, including hydraulic modeling, reliability modeling, and geotechnical analyses. The LOS criteria recommended to SFPUC for development of the AWSS program was water delivery reliability, measured both Citywide and in defined geographic areas called fire response areas (FRAs). LOS performance objectives were selected for development of the program alternatives with a minimum for each FRA and a resulting minimum average for San Francisco as a whole. A condition and needs assessment was performed, and projects were identified and sized utilizing the hydraulic and reliability modeling tools developed for the project. Selected projects were grouped into program alternatives, with the preferred program selected by an analytical hierarchy process.

An independent fire protection system, known as the Auxiliary Water Supply System (AWSS) was implemented after the 1906 San Francisco earthquake to be used as the secondary defense against fires in the event the municipal water supply system fails or underperforms. The system has two saltwater pumping stations, Pump Station 1 and Pump Station 2, that deliver salt water to the AWSS following an earthquake and ensuing fire. The inlet tunnels to Pump Stations 1 and 2 are essential links in the system. This paper describes the assessment of the seismic performance of the inlet tunnels. Two damage scenarios for Pump Station 1 and one damage scenario for Pump Station 2 are discussed and remediation options are presented.

Thrust restraint design practices have evolved over the years, based on experience, theoretical research, and laboratory/field testing. Such tests have been conducted by different research entities and pipe manufacturers, most often to study and/or provide verification of the restraint design theories and to validate soil parameters. However, due to the wide ranges of pipe material, size, configuration, and soil conditions, there are considerable gaps in the available test data. Such gaps result in large-scale interpolations and extrapolations to fit the data to many common thrust restraint design conditions. In an attempt to fill some of these data gaps, additional field or laboratory tests are conducted from time to time. By their very nature, thrust restraint tests are expensive and time consuming. As tests on large-diameter pipes are more expensive, most of the field tests have been performed on small-diameter pipelines. The results from small-diameter pipelines may not be readily applicable to large-diameter pipelines. While recognizing these limitations, the need for field testing of large-diameter pipelines to study thrust restraint behavior is desirable not only to understand the theory but also to improve design practice. Understanding the mechanisms of soil-pipe interaction is essential to modeling the means by which thrust forces are resisted by the soil. An important parameter in determining the frictional resistance mechanism is the soil normal pressure distribution around the pipe. While understanding of this mechanism has improved, test data verifying the actual pressure distribution are very limited. Recognizing the need for additional testing and the high cost of conducting these tests, the ASCE Task Committee on Thrust Restraint Design of Buried Pipelines (Task Committee) has undertaken the task of reviewing available data, identifying the data gaps and research needs, and recommending the types of research and tests to help maximize the useful data gained from these tests. Some recommendations for test configurations will also be included to encourage consistency in testing methods. It is the intent of the Task Committee that this paper function as an invitation to others in the pipeline industry to partner with us to continue the development and improvement of a more unified thrust restraint design practice.

The City of Corpus Christi, 8^th largest city in Texas, is a booming, coastal city in south Texas that relies heavily on both tourism and the oil and petrochemical industry as the main engines driving growth and redevelopment. As a result, the need to make substantial improvement to the aging sanitary sewer infrastructure, which is constructed primarily of vitrified clay pipe lines that have been in service for more than 50 years, has increased. The City's wastewater collection system taxed by the development has experienced significant amounts of infiltration and inflow (I/I), debris deposits, collapsed lines, and cave-ins. To address the growing demands on the infrastructure and provide the ability to quickly mobilize to an emergency type repair, the City has established a program of implementing various indefinite delivery/indefinite quantity (IDIQ) contracts for wastewater system rehabilitation. This paper will discuss the process the City of Corpus Christi went through to implement the rehabilitation program and outline its results, rehabilitation procedures for pipe lines, and lessons learned. This paper provides details on the evaluation and prioritization for project selection, the development of specific projects, experiences with projects constructed, and the implications of the rehabilitation program in terms of reduction in sanitary sewer overflows and cost savings for emergency repairs.

A 72-in. water transmission main was installed in the early 1960s to provide water to the southeastern portion of the City of Dallas Water Utilities (DWU) service area. This prestressed concrete cylinder pipe (PCCP) was at risk of being exposed by the Trinity River due to river bank erosion, compromising its integrity. Several options were evaluated to protect the pipeline and also to minimize the impact to the surrounding area. The options varied from pipe relocation to bank stabilization. An electromagnetic (EM) inspection was performed and only six joint locations were found to be distressed indicating the line was in good condition, making the pipe replacement option less desirable. Using the results of an investigation of soils in the area, cost analysis, EM results, and long-term client interests, bank stabilization in the form of rock anchors and gabions was ultimately recommended. This cost-effective approach was estimated to save , more than $13 million in construction costs as compared with replacement of the pipeline. This paper discusses the alternatives evaluation, design phase, required permitting with the U.S. Army Corps of Engineers, and the risks associated with the construction phase on the banks of a major waterway.

Understanding soil-structure interaction behavior of the pipe-soil interface is essential in the characterization and assessment of thrust restraint resistance mechanisms in buried pipelines. Two primary forms of resistance mechanisms, axial and transverse, contribute to the resistance of unbalanced thrust forces that arise at a bend, valve, tee, or other similar sources of thrust in a buried pressure pipeline. The individual contribution from each mechanism would depend on the material properties and constitutive relations of the pipe segments, pipe joint type and configurations, soil, and the pipe-soil interface; internal and external loadings on the pipeline; installation conditions; and relative magnitude of pipe-soil movement. In the water/wastewater industry, pipeline designers frequently rely on guidance from AWWA standards and design manuals. These guidance documents are developed by distinct material-specific standard committees, and the contents are based on differing simplifying assumptions, theories, and design philosophies, and are often uncoordinated. In most cases, the rationale behind the recommended soil parameters is typically undocumented, based on unidentified assumptions, or otherwise not considered directly in guidance documents. This practice leads to inconsistent guidance on selection of soil parameters for use in the soil-structure interaction analysis of different pipe materials and makes improvement of design practices difficult. This paper presents a review of factors that influence frictional resistance with and without transverse movement of buried pipe, and the laboratory and field tests performed to establish frictional coefficient of pipe-soil interface for various pipe materials. Based on this review, the paper discusses the appropriateness of the reported friction coefficients for different pipe materials and/or coatings. Recommendations for the soil and pipe-soil interface parameters have been presented where appropriate based on soil mechanics principles and available results from laboratory or field experimentation.

Understanding soil-structure interaction behavior of the pipe-soil interface is essential in the characterization and assessment of thrust restraint resistance mechanisms in buried pipelines. Two primary forms of resistance mechanisms, axial and transverse, contribute to the resistance of unbalanced thrust forces that arise at a bend, valve, tee, or other similar sources of thrust in a buried pressure pipeline. The individual contribution from each mechanism depends on the material properties and constitutive relations of the pipe segments, pipe joints, soil, and the soil-pipe interface; internal and external loadings on the pipeline; and installation conditions. In the water/wastewater industry, pipeline designers frequently rely on guidance from AWWA standards and design manuals. These guidance documents are developed by distinct material-specific standard committees, and the contents are based on differing simplifying assumptions, theories, and design philosophies and are often uncoordinated. In most cases, the rationale behind the recommended soil parameters is either undocumented or based on unidentified assumptions. This practice leads to inconsistent guidance on selection of soil parameters for use in the soil-structure interaction analysis of different pipe materials and makes improvement of design practices extremely difficult. The soil parameters employed to assess transverse soil-structure interaction behavior are related to the analysis method adopted, such as passive resistance theory, bearing-capacity theory, beams on elastic foundation theory, and P-y curves for the case of transverse resistance. The lateral resistance to the transverse movement of the pipe depends on a variety of factors, including the type of soil, the depth of embedment, the magnitude of the pipe movement against the soil, and the direction of the pipe movement. Different lateral stiffness or subgrade soil moduli are to be expected for a horizontal bend, a vertical upward bend, and a vertical downward bend located in similar soil conditions. P-y curves existing in the literature for lateral pile analysis problems require modifications for application to pipelines with transverse loading. This paper reviews different theories for transverse soil-interaction behavior and identifies P-y curve theories appropriate for such analysis of restrained pipelines located in different types of soils. It presents general approach and derivations of P-y curves for pipelines located in sands and clays. The paper also provides recommendations for soil parameters needed to model lateral resistance of pipelines to transverse movements. These parameters include friction angle, cohesion, unit weight, subgrade modulus, and strain corresponding to one half of the maximum principal stress difference.

Large-diameter transmission mains are a critical element of water distribution systems, because a failure can be catastrophic and result in extended service interruptions for many customers, along with associated water quality concerns. Recent advancements in polymer science have resulted in the production of high-performance large-diameter (16-in. and larger) high-density polyethylene (HDPE) pipes capable of withstanding high pressures. However, the use of HDPE pipe for large-diameter pressure applications has been limited due to lack of adequate experience and perception issues associated with HDPE for pressure pipe applications. As such, this paper provides a review with respect to the experience to date with large-diameter HDPE for water transmission mains via case studies from water utilities in the United States and around the globe. The case studies presented herein are being compiled as a part of an ongoing wider scale research project on durability and reliability of large-diameter HDPE pipe (Water Research Foundation #4485). At the time of this manuscript submission, case studies have been collected by the project team with HDPE pipes ranging from 20 to 42 in. in diameter and spanning a variety of soils, landscapes, and surface conditions. While a full evaluation of a particular pipe material requires several other aspects to consider, the goal of this paper is to present an independent, overall review of large-diameter HDPE pipe for water transmission applications.

The City of Portland, Oregon, Bureau of Environmental Services (BES) recently completed a wastewater sewer system plan to address capacity and structural deficiencies in the combined and separated sewer systems. BES developed this plan by applying asset management principles for business risk (in dollars). Risk is defined as the product of consequence of failure (in dollars) and likelihood of failure (probability). Projects were developed to mitigate the deficiencies and meet BES levels of service (LoS). BES considered impacts of structural and capacity failures, including sinkholes from collapsed sewers, basement sewer backups, surface flooding, and emergency repairs. This paper focuses on the assessment and mitigation of capacity risk by describing 1) the modeling system used to characterize and develop alternatives for mitigating the capacity LoS deficiencies and 2) how asset management, risk-based methods were used to select preferred alternatives and prioritize the implementation of recommended projects in the capital improvement program (CIP). These projects will eliminate or significantly reduce street flooding risk and basement sewer backup risk (BSBR) for the 25-year design storm, which is a BES technical LoS related to the protection of public health.

Today the potential for AC-induced corrosion damage to buried pipelines located near high-voltage transmission lines is greater as the electrical currents are increasing to meet higher load demands. Frequently the rights-of-way of transmission lines and buried pipelines are adjacent and separated by 75 to 100 ft, which places the pipeline in the strong magnetic field of the transmission lines. These fields induce voltages that can exceed safe step-and-touch potentials and cause accelerated pipeline corrosion due to high discharge current densities. In the early phases of pipeline design, analysis of the potential for induced AC interference can identify the locations most susceptible so that mitigation measures can be addressed. On a long, cross-country water transmission line project for Tarrant Regional Water District in Texas, initial engineering studies identified more than 40 high-voltage transmission line crossings and multiple areas of parallel pipeline and transmission line rights of way that extend for several thousand feet. After identifying areas where the probability of interference was high, analysis software was employed for use in quantifying the induced AC voltage along the pipeline. The software requires detailed dimensional parameters relating to the transmission line towers, heights and horizontal separation of the circuit conductors and shield wires, electrical parameters of the conductors, phase identification, and the maximum phase current in each conductor. Also required are pipeline dimensional parameters, location of insulating joints, coating thickness, coating conductivity, and soil resistivity. Each area of potential interference is analyzed by modeling the area in small increments; these increments are generally bordered by a change in direction of the pipeline alignment or transmission line or the approach/departure of additional transmission lines. After all of the required electrical and dimensional parameters are entered, the area analysis calculations are used to produce graphical displays of the induced-AC voltage and pipeline current as a function of distance along the pipeline. These graphics provide pipeline design engineers with critically important information that can be integrated early in the design phase. This paper will provide a brief description of the induced-AC interference phenomenon and provide several examples that identify the relationship between the magnitude of induced-AC voltage and specific physical and electrical parameters.

The external polyurethane coating on welded steel pipe was selected for its properties as an excellent means to control corrosion, to minimize cathodic protection current requirements, and to help the pipe achieve a trouble-free, 100-year design life when buried in an earthen environment. For long, cross-country water transmission pipeline projects, it is not unheard of to have procurement segments in excess of 10-15 mi and diameters in the 84 in. to 108 in. range. For such projects, it is anticipated that pipe manufacturing and coating production will far outpace a contractor's field installation and will subsequently lead to short- and long-term storage of pipe whether at a staging yard or strung out along pipeline alignment. Due to the magnitude of these types of projects, it is anticipated this stored pipe may experience extended time above ground in extreme temperature and in the presence of solar light (radiation), including ultraviolet radiation (UV), which imparts thermal energy. A study was conducted at the plants of two steel pipe manufacturers in the Dallas Fort Worth (DFW) metroplex from June to September 2013. Sample pieces of large-diameter (72 in. to 96 in. diameter) polyurethane-coated steel pipe had been exposed to elements for periods of time, from one to two years, were monitored for surface temperatures during the peak of summer. Pipe surface temperatures measured in this study exceeded 150 degrees F. This paper will describe the test set-up and procedures, present results of field and subsequent laboratory measurements, and examine how the polyurethane coatings responded following exposure to the Texas sun.

Portland's Bureau of Environmental Services (BES) completed the sewer pipe rehabilitation plan to address structural deficiencies in the combined and separated sewer systems. The resulting eight-year, $123 million capital program used an asset management framework to identify and prioritize projects that mitigate structural risks and meet BES levels of service. Projects that provide cost-effective risk reduction were prioritized and implemented to address the most critical and urgent problems first. Sixteen sewer rehabilitation projects were created to group the work into cost-efficient sizes for design and construction. BES staff and consultant design teams together developed detailed designs for the 16 projects each in the range of $4 million to $10 million in costs. Significant work in closed-circuit television (CCTV) inspection, risk evaluation, and design is rapidly accomplished to refine which pipes are in scope and their rehabilitation methods. Technology-based contracts for cured-in-place pipe lining (CIPP) are used alongside traditional construction methods to implement the designs.

In 2010, the North Texas Municipal Water District (NTMWD) contracted Freese and Nichols, Inc. (FNI), to begin the design of a 54-in. diameter pipeline in the northern end of its service area to meet the future growth projections of an area north of Dallas that has seen some of the highest population growths in the nation in the last 10 years. The project is named the North McKinney Pipeline, and the initial design is for two phases of an anticipated four-phase project. The North McKinney Pipeline is approximately 6.5 mi in length and was proposed as a 54-in. diameter treated water line. The line begins in the City of Lucas, travels north into the Town of Fairview, and then into the City of McKinney, which is the north end of the first two phases of this pipeline. The pipeline was designed to deliver needed capacity to southeast McKinney and Fairview and eventually on to the north and western areas of McKinney. As with many typical transmission pipelines, this project began as a fairly straightline conceptual layout, and during the preliminary design phase the scope was to develop three to four possible route options for the proposed pipeline. The area where this pipeline was planned to be constructed is generally mid-to-lower density residential land with some state highway frontage that currently has schools, small manufacturing facilities, and residential lots. No potential conflicts were foreseen for a route through the existing areas that would be necessary to avoid or have special construction considerations outside normal pipeline construction methods. The initial route study and alignment selection began with four to five route selections. NTMWD and FNI agreed on an initial route for the proposed pipeline from the preliminary route alternatives. However, once the route was selected and request for permission to enter properties notifications were sent out, a large amount of opposition from residents and the Town of Fairview was presented to NTMWD. At the request of NTMWD, the route selection process to develop and analyze several more possibilities for route alternatives was restarted. This paper will present the numerous different route alternatives developed for the North McKinney Pipeline through Lucas, Fairview, and McKinney. The reasoning, development process, and route alternative drivers that led to the development of 17 pipeline route alternatives will be detailed throughout the paper. Also, the paper will explore the demands that residents and cities can put on a water district and the influence they can have on pipeline routing and development.

The Upper Trinity Regional Water District (UTRWD) currently provides treated water service on a wholesale basis to towns, cities, and utility districts throughout Denton County and a portion of Collin County. UTRWD serves the majority of its members and customers directly through its regional treated water system (RTWS). The RTWS comprises the Tom Taylor Water Treatment Plant, the Tom Harpool Water Treatment Plant, ground storage tanks, an elevated storage tank, pump stations, and approximately 87 mi of large transmission pipelines. UTRWD's members and customers subscribe for an amount of water that is delivered to them at their point(s) of delivery. UTRWD maintains sufficient capacity in its finished water system to deliver the subscribed capacity to its members and customers. To ensure a reliable system, UTRWD retained CH2M HILL to perform a hydraulic analysis for several demand scenarios for customers in the western portion of their system. The analysis, which reviewed flows ranging from 10-26 mgd, indicated that several pipeline diameter combinations ranging from 30-42 in. and two pump station options should be considered. Additionally, two pump station locations and two alignments were available for construction. This paper will discuss how running numerous hydraulic model scenarios revealed several possible pipe combinations for near- and long-term demands. It will also discuss how the inclusion of these combinations as bid alternates with multiple pipe materials encouraged competition and enabled UTRWD's board to select the most advantageous option.

The prestressed concrete cylinder pipe (PCCP) North District Wastewater Treatment System 72-in. Interceptor N-9 Force Main (FM), approximately five miles long, conveys wastewater along NW 159th Street to the MD-WASD Northwest District Wastewater Treatment facility. The 72-in. embedded PCCP portion of the pipeline was originally constructed in the late 1970s under Contract S-168. On June 18th, 2010, a portion of the 72-in. PCCP force main experienced a catastrophic failure just west of Northwest 17th Avenue. The corresponding failed pipe, along with an adjacent pipe segment, were removed and replaced at that time. The existing 72-in. FM is located under streets in a heavily populated single family residential area along NE 159 Street between NE 2nd Avenue and NE 10th Avenue and within a high-density residential multifamily area alongside the Biscayne Drainage Canal (C-8), including the Evangel Church International (Evangel Temple of Miami), the Christ Community Church (First Alliance Church of Miami), and Oak Grove Elementary. The project site is located within the City of North Miami Beach, Miami-Dade County, and the City of Miami Gardens. The area in the following limits falls under the City of North Miami Beach: from NE 10th Avenue along NE 159th Street to NE 8th Avenue. Miami-Dade County falls under NE 8th Avenue, along NE/NW 159th Street to the intersection of NW 6th Avenue, along NW 6th Avenue from NW 159th Street to Biscayne Canal (C-8), and along the northern bank of Biscayne Canal (C-8) to NW 155th Drive. The rest of the project site falls under the City of Miami Gardens. A design-build criteria package was proposed for the replacement/rehabilitation of a 72-in. sanitary sewage FM along Northwest/Northeast 159th Street between Northwest 17th Avenue and Northeast 10th Avenue. This rehabilitation/replacement analysis and feasibility study detail the findings of investigations and alternative analyses to provide recommendations for a proposed FM rehabilitation/replacement. The key decisions are to determine whether to rehabilitate or replace (via trenchless or open-cut construction methods) and which of the commercially available rehabilitation methods are suitable for this particular application Open-cut replacement has been the standard practice in the past, but its preferential use over trenchless techniques has been significantly diminished in the past two decades—particularly in the wastewater sector. Awareness of the indirect and social costs associated with utility work in congested urban areas has encouraged the use of full costing approaches in the selection between open-cut replacement and trenchless rehabilitation or replacement methods. The selection of the trenchless rehabilitation approach involved a selection process followed by a more detailed evaluation of the technologies. We excluded some technologies that were obviously not suitable for this application. The remaining technologies may be suitable but have different cost, risk, setup area requirements, life cycle performance, compatible materials, and environmental impacts. Specifying a single technology in this feasibility study may have a negative impact on the competitiveness of bids received. Ideally, a level playing field is created when bidders can propose one of several suitable technologies, so that a fair competition is created with similar performance characteristics specified for each technology.

Three case studies are presented for the application of electrical resistivity and shear wave velocity geophysical techniques to pipeline projects in marine, terrestrial, riverine, salt pond, and estuarine environments. The first case study used resistivity mapping to delineate the geologic stratigraphy and define the boring profiles for the construction of four 20-in. diameter, 165 and 220 m long horizontal flushing channels at a resort property in the Caribbean. The profiles traversed terrestrial, marine, and hypersaline pond environments, and the completed flushing channels resulted in the conversion of a stagnant, 13-acre salt pond into a functional marine habitat. The second case study utilized resistivity and shear wave velocity mapping in a riverine environment in Florida to direct the location of a 20-in. diameter, horizontally-drilled gas line traversing three river crossings. The geophysics provided a detailed geologic stratigraphy of the sub-surface sediment and rock units and further allowed for identification of karst features through which the boring profile would encounter loose, flowing sediments and drilling fluid circulation losses. The results allowed for guidance of the horizontal boring profile through dense shell and limestone strata. The third study utilized resistivity and shear wave velocity mapping on a section of the Hudson River to identify the top of rock for aid in designing a directional boring profile. Past marine seismic reflection surveys were unsuccessful in this environment due to the presence of gas pockets within the overburden sediments. However, the resistivity data beneath the seabed differentiated the sand, gravel, clay, and rock units, which were confirmed by correlation to borings collected on the landward side of the boring route. Shear wave velocity mapping was utilized for the landward completion of the route. The seismic data identified the top of dense rock to within 1 m of what the boring data showed. Results of these studies have provided the geologic framework for engineers to implement successful construction strategies in designing subsurface boring profiles and show the invaluable nature of utilizing geophysics as a first-order technique in guiding rapid, accurate, and cost-effective geotechnical investigations.

The proposed Arkansas Valley Conduit (AVC) is a congressionally authorized feature of the Fryingpan-Arkansas (Fry-Ark) Project located in southeastern Colorado. The AVC would be a bulk water supply pipeline designed to supplement or replace existing poor quality water and meet existing and future municipal and industrial water demand in the Lower Arkansas River Basin. Physical features of the AVC would include approximately 370 km (230 mi) of buried pipeline, a water treatment plant, water storage tanks, pump stations, and other related facilities. Forty water providers would participate in the AVC. In 2010, an environmental impact statement (EIS) study was initiated to disclose the potential environmental consequences associated with constructing and operating the AVC. Alternative pipeline routes had to be identified as a part of the EIS process. A structured alternative development and screening process identified a wide range of technical and conceptual options and formulated them into a set of alternatives that address key issues. The purpose of this paper is to describe the four-step process used for the AVC to develop and evaluate alternatives. Because the service area for the AVC is large and involves so many water providers, each with unique connection requirements, the challenge during the alternative analysis stage was to identify alternative corridors that addressed the purpose and need of the project, but did not require an extensive area to analyze for the EIS. Too narrow of a corridor for an alignment would limit the ability to make minor alignment changes based on the results of the EIS process. A corridor too wide could create excessive EIS studies and unnecessary costs and delay the process. An innovative methodology was developed to establish a range of reasonable alternatives meeting the purpose and need of the project. This methodology provided maximum flexibility for identifying and addressing the key needs of the project while minimizing the area needed for the EIS evaluation. This approach proved especially valuable because the final preferred alternative selected ended up being a "hybrid" of various alignment routes and components evaluated during the EIS process. This paper outlines the background, strategies, and process to identify, screen, and evaluate alternatives for the EIS. The paper offers suggestions to facilitate the alternative evaluation process for others who may have similar challenges in the future.

Trench design for a flexible pipe is second nature to most engineers. Trench width is typically based on a balance of safety considerations, soil strength, and soil stability to provide reasonable side support and space for compaction. One topic that is generally considered outside the confines of standard pipe design is calculating the minimum separation between parallel pipelines. Providing the correct pipe spacing whether installed in a common trench or next to an existing line is critical to prevent catastrophic failure. This failure can occur from pipe collapse or undermining of the soil support of an adjacent pipe. The authors present a method for calculating pipe spacing using measured soil parameters: soil slip angle and cohesion. The paper will provide an in-depth analysis of the full approach and include sensitivity tables that show the interrelationship of each parameter and how it influences the trench width and depth. This method was used to design the spacing of a parallel 36-in. and 60-in. pipeline and the challenges encountered during soil testing.

In a cooperative agreement, the Tualatin Valley Water District (TVWD) and the Oregon cities of Hillsboro, Beaverton, Tigard, and Tualatin have embarked on the development of a new water system. The new water supply system will serve to support the growth and economic viability of the communities and will provide greater redundancy and resiliency, which is particularly important given that the region is seismically active. These communities are located to the west and south of Portland, Oregon, and collectively serve more than 400,000 customers. The new water supply will withdraw water from the Willamette River through the existing Wilsonville intake facility. A new treatment plant will be constructed near the existing Wilsonville Water Treatment Plant and water will be transmitted from the new treatment plant to a terminal reservoir approximately 20 mi north. From the Terminal Reservoir, transmission pipelines will be routed to deliver water to each of the project partners. Critical to the success of the project is identifying and securing a preferred route for the pipelines and siting the terminal reservoir. Much of the area is developed where the pipelines will be routed. The areas that are not developed may be subject to improvement at any time. The location of the terminal reservoir is elevation critical. The desired elevation is in a very narrow band of undeveloped but highly desirable property. With the project not needing to be operational until 2026, the dilemma facing the project partners is how to identify and secure the needed reservoir site and pipeline corridors while not constructing facilities that will not be utilized for several years. To meet their needs, the project partners have embarked on a project to develop a preferred alignment for the pipeline and a site for the terminal reservoir that balances the technical needs of the project with financial concerns, social issues, environmental concerns, and long-term project resiliency. The goal of this initial phase will be to select the most appropriate alignment and sites and secure them for the long term to ensure a viable project. Where necessary, segments of the project may be constructed in advance to work cooperatively with road projects and to comply with permit conditions or as other opportunities to jointly construct a portion of the infrastructure arises. This paper will outline the challenges faced by the project partners and present the innovative and engaging techniques used to help ensure a long-term and reliable water supply to their customers in the Pacific Northwest.

A risk assessment model is developed to identify and prioritize the most vulnerable pipes needing immediate rehabilitation or replacement based on the highest probability of failure and economic impact. A pipe's probability of failure is determined using the physical condition of the pipe such as installation year, age, material, and break history. The model then considers various economic degrees of impact relevant to the rehabilitation or replacement of these pipes, for example raw material costs, customer criticality, land use, demand, pipe material, and traffic impact. This developed risk assessment model, in conjunction with WaterCAD and geographic information systems (ArcGIS) software, was applied to a real water distribution system in California. Out of more than 3,500 individual pipe segments, the model was able to identify only six pipes requiring immediate replacement. Developing and testing this risk assessment model with real city data effectively demonstrated its practicality and easy application to a real water distribution system. If utilized, city officials can quickly identify and prioritize pipes needing rehabilitation or replacement by using reliable, up-to-date water distribution data from their city with this risk assessment model.

Polyurethane for coating of steel water pipe is used as an effective corrosion control system in the water and wastewater markets. As use has increased, questions have arisen regarding the ability of polyurethane to maintain its integrity for buried application while stored above ground and exposed to the elements. Polyurethane used for steel water pipe will typically be specified to meet AWWA C222, which requires the use of aromatic polyurethanes that result in a resilient and flexible coating and lining system. Aromatic polyurethanes can however be susceptible to surface degradation from ultraviolet rays and can chalk or discolor when left in the sun for long periods. Historic testing in the coating industry that is related to weathering effects focuses on color changes or color shift for architectural purposes, but for buried pipe, discoloration is not a concern. Potential loss of the coating film mechanical and chemical properties due to thermal cycling above and below the glass transition temperature of the material during the exposure are of greater interest. Testing was performed on samples of polyurethane applied to 96-in. diameter steel pipe manufactured and coated per AWWA C222 in Saginaw, Texas. Multiple test samples were removed for testing from the pipe, which had been stored in Saginaw for more than 24 months. The pipe was monitored over a period of time during the summer months to get an indication of the temperature fluctuations the coating was exposed to on a routine basis. Hardness and adhesion testing was performed on the coating as well. The samples were subjected to nano-indentation tests to determine any modulus shift and testing to determine chemical changes from the exterior of the coating to the steel surface. This paper will discuss the results of the testing of this aged polyurethane coating and discuss possible changes in the physical properties of the coating and its capability to provide its intended corrosion protection and service after 24 months in the Texas sun. Recommendations to address extended exposure of buried aromatic polyurethane coatings will also be discussed.

The Metro Wastewater Reclamation District (District) in Denver, Colorado, is currently constructing a new wastewater treatment plant, referred to as the Northern Treatment Plant (NTP), to serve the north suburban Denver metropolitan area. As part of the NTP program, the District is also constructing a new interceptor to convey wastewater to the NTP site. The new interceptor is referred to as the South Platte Interceptor (SPI). Designing a large sewer interceptor through an urban corridor is always challenging, however, because the SPI alignment was required to parallel the South Platte River, a unique set of technical issues had to be addressed. The paper/presentation will focus on the following three technical challenges and the engineering analysis performed in preparing the design to address them: (1) Where the interceptor must be installed adjacent to meandering river bends, it must be either protected from erosion or further meandering of the river must be prevented. (2) Where the interceptor parallels gravel pit lakes adjacent to the river, construction activity must not impair the ability of those lakes to collect and store water. (3) Construction dewatering adjacent to a river can have a high potential for construction claims. The geotechnical exploration program and dewatering specifications must be structured to minimize the District's risk exposure. As a result of early identification of the technical challenges and the collaborative efforts of pipeline designers, technical experts, and District staff, solutions were developed that satisfied all of these challenges and allowed the project bids to come in below budget. This paper/presentation will describe the challenges that were faced and discuss the range of solutions investigated and incorporated into the design.

The Fort Worth Water Department has about 350 sq mi (906.5 sq km) of service area and 3,560 mi (5,729 km) of sewer collection system piping. Through major investment in collection system master-planned capacity improvements and collection system piping renewals and by implementing a strong sewer preventive maintenance (PM) program, the department has achieved a large reduction in the number of sanitary sewer overflows (SSOs) occurring in the system during the past 20 years, even while the system was growing rapidly. To build upon such progress and reduce SSOs even further, the department implemented a clear/inspect/fix (CIF) process, which follows SSOs and sewer stops with closed circuit television (CCTV) investigation to identify and address the root causes of the events. In addition to CCTV, geographic information system (GIS) and Maximo work management technologies have been utilized in this effort. Since its implementation in 2010, the CIF process has contributed significantly to an ongoing reduction in SSOs. In fiscal year 2013, the number of SSOs per 100 mi (161 km) of collection system piping fell below 10 for the first time in the department's recorded history.

Planning for a complex subsurface project includes several items of risk for the designer, most importantly the risk of a changed subsurface conditions claim by the contractor or an errors and omissions claim by the owner. Mitigation of this risk is typically accomplished by taking numerous test borings, which is difficult for long linear projects such as pipelines. A certain amount of geologic evaluation and judgment is necessary to optimize the subsurface exploration program so that resources can be focused on potential problem areas. Major geotechnical issues for trenched pipelines include depth to rock or hard material, soil properties especially stability and stand-up-time, hydrologic conditions of water table depth and potential for inflows, and presence of anomalous conditions such as sinkholes or landslides. Quantifying these evaluations is important to know when enough data has been collected to validate the accuracy and completeness of the subsurface investigation. As more and more projects move into the design-build type of construction, it becomes ever more important to quantify the results of the exploration program.

The use of differing materials for distribution and transmission pipelines with equivalent outside diameters within water and waste water systems is many times deemed by the owners as an "apples to apples" comparison when evaluating the initial construction cost. The scope of this paper will focus upon the significant energy costs that are saved (or expended) over the life of the system as a result of the decisions made during the design and specifications stage of a project in determination of the pipeline material to be utilized. It will be shown that use of pipeline materials with larger inside diameters can save a utility virtually millions of dollars in energy costs over the life cycle of the pipe. Serving as a former lead executive for the nation's largest investor-owned water utility, I am intimately aware of the scrutiny of customers when it comes to supporting escalating operating costs of a utility. Construction projects are easier to identify and substantiate. This paper will find through use of present worth analysis that utilities are considering, or in many cases disregarding, the sustainability of energy operating costs within their utility by taking into account (or not) the inside diameter of pipeline materials utilized within their system. The decision by utility system owners to utilize the least expensive pipeline materials in construction projects may over time create very significant energy operating costs that can ultimately affect the sustainability components of the system. These escalating costs when not identified at the outset of project design will assimilate the boiled frog theory, incrementally rising each year unnoticed until potentially millions of dollars are being expended in energy costs over the years as a result of smaller inside diameter pipe.

Establishing the right of way (ROW) is very important in pipeline projects in urban areas. ROW has increasingly become a critical path item for large-diameter pipeline projects, especially for a regional pipeline that extends for several miles in an urban area. This paper will discuss a few of the challenges and considerations involved with ROW acquisition for a large-diameter pipeline in urban areas. The type of ROW acquisition is an important consideration; both fee simple and easement acquisitions have advantages and disadvantages that need to be considered. In developed urban areas where there are few options for a pipeline corridor, it is important to maximize the use of existing public ROW and limit the impact to local businesses and residences as much as possible. To establish the required width of the ROW, the engineer must consider the ROW acquisition necessary for the installation and future maintenance and operation of the pipeline. In large urban areas, regional pipeline projects have the potential to cross through multiple cities and jurisdictions. It is important to involve the cities in which the pipeline will be constructed early on in the alignment study process to coordinate logistics. Approval from these cities may be required in the form of a formal interlocal agreement to share the public ROW. Existing public ROW may prove to be the best alignment; however, in many cases, there may not be adequate existing public ROW to accommodate the pipeline. In these cases, additional ROW acquisition would be required. Consideration could also be given to an alignment along an existing utility or railroad corridor when feasible. The number of parcels affected by the acquisition along the pipeline corridor is an important consideration during the pipeline alignment study. It may be prudent to define a corridor through an area of large parcels with undeveloped lots when possible, which would require negotiation with fewer owners. After an alignment has been established and the number of parcels affected by this alignment has been determined, right of entry onto the property will be required for preliminary design and survey purposes. These are just a few of many key factors that should be considered when determining the required ROW acquisition for a large-diameter pipeline that will be discussed in this paper.

Many utility asset management programs have been developed following the U.S. Environmental Protection Agency (EPA) core definition of maintaining a level of service at the lowest life cycle cost. Most utilities, however, only incorporate performance measures into their asset management plans. A holistic approach to asset management is more beneficial because it takes into account the short- and long-term goals of the utility and can provide better service socially, economically, and environmentally. An analysis of the Town of Blacksburg wastewater utility's practices and data collection was performed using a holistic asset management framework developed at Virginia Tech. This theoretical framework supports the three key aspects of asset management: performance, sustainability, and resilience. Where gaps were identified, recommendations were made as to what practices, goals, and data the Town can add to its current plan so that its program is more holistic.

The Martin Hill Transmission Main is one of several distribution system improvements designed to bolster the reliability of water supply to the City of Austin's northwest service area. The project includes the construction of approximately 15,000 linear ft of 54-in. welded steel waterline, which will provide much-needed transfer capacity between two of the City's larger reservoirs. The alignment traverses environmentally sensitive areas and public school frontage, both of which presented unique challenges in the planning, design, and construction of the project. Included in this paper is a detailed account of the efforts made by design engineers and Austin Water Utility professionals to navigate the regulatory requirements essential in moving this project into construction while incorporating provisions to protect the environment and area residents. The location of the Martin Hill Transmission Main is within the Edwards Aquifer Recharge Zone, an environmentally sensitive area home to several endangered species. The recharge zone is characterized by karst features, or voids in limestone through which water can percolate and reach the aquifer. Minimizing the disturbance of these features during construction was a priority of preliminary engineering, which included a horizontal and vertical route evaluation. Runoff from trench excavation into the recharge zone could potentially threaten water quality and the habitat of endangered species. The use of subsurface geophysical surveys was employed to characterize the limestone during the preliminary engineering phase. The results of this investigation were used to identify the pipeline alignment with the least potential for traversing sensitive karst areas. In detailed design, this information was used in developing the pipeline profile. The depth of the pipeline required careful balance between protecting the City's assets and minimizing the potential for water in the trench to eventually reach several protected karst features (caves) through subsurface migration. In addition to addressing these important environmental constraints in the preliminary and design phases of the project, a major revision to the alignment was made early in design as a result of a new City ordinance that extended the protection of trees larger than 24-in. in diameter. The ordinance established an extensive review process for proposed tree removal, which could add more than six months to the project timeline and could or could not result in approval to remove the trees. After careful consideration of the time and cost benefits of other alignment alternatives, it was decided that a portion of the Martin Hill project would be located in the pavement of a road serving a public high school. Although this adjustment in alignment enabled more timely environmental permitting review, the relocation to the pavement and proximity to the school made it necessary to incorporate traffic control design and schedule restrictions into the project.

The wastewater collection and water distribution systems in the United States are deteriorating at an alarming rate. The ever-growing need for rehabilitation and replacement of these systems led to the birth of a research program by the United States Environmental Protection Agency, Innovation and Research for Water Infrastructure for the 21st Century, which focused on addressing the water infrastructure needs. There is a need to responsively manage energy and environmental resources, which calls for the use of evaluation tools to compare competing alternatives with a view to adopt the most environmentally friendly alternative. This paper gives an overview of the environmental value engineering (EVE) methodology, which evaluates the environmental impact and contribution of built alternatives in terms of solar emergy through 10 phases of a project's life cycle. Emergy, a measure of real wealth, is defined as the sum of the available energy of one kind previously required directly or indirectly through input pathways to make a product or service. The paper also gives results of an EVE analysis of horizontal directional drilling (HDD) versus open-cut construction during a pressurized water mains installation process.

To maintain sustainable growth in the Antelope Valley region of California, the Antelope Valley-East Kern Water Agency (AVEK) has implemented the Water Supply Stabilization Project No. 2. The project consists of the development of a 1,500 acre (607 ha) groundwater recharge and extraction field that will recharge water from California's State Water Project (SWP) during periods when SWP supplies exceed demands and will extract up to 90% of the banked water during periods of high demand when SWP supplies are low. During the first phase of the project anticipated to be more than $75 million in capital improvements at completion, AVEK has installed more than 22.5 mi (36.2 km) of 48-in. (1,200 mm) cement mortar lined and coated (CML&C) steel pipe, 3.5 mi (5.6 km) of 12-in. to 30-in. (300 mm to 750 mm) PVC/CML&C steel well collection pipelines, and five 36-in. (900 mm) CML&C steel pipe turnouts to an existing 60-in. (1,500 mm) prestressed concrete cylindrical pipe.

The North Charleston Sewer District (NCSD) System includes 62 pump stations and approximately 475 mi of gravity and force main piping. This infrastructure serves approximately 100,000 customers over a 59 sq mi service area. The Felix C Davis Wastewater Treatment Plant (WWTP) is permitted to treat 27 MGD and is the only plant utilized by NCSD. Currently, the plant averages approximately 15 million gallons per day (MGD) and recently completed an expansion to treat 34 MGD.

The City of Saskatoon (City), with a population of 215,000, operates a water treatment plant on the west bank of the South Saskatchewan River (SSR) and a river pump station located across the river on the east bank. A 1,500-mm diameter pipeline river crossing connecting the pump station and the water treatment plant was required and subsequently constructed using an open-cut cofferdam method. This paper discusses the design team's challenges in formulating the final design in support of the cofferdam open-cut construction method. Interesting design elements included a river hydraulic assessment, the use of rock spur, articulated concrete mat to protect the earthen cofferdam, siltation curtains for aquatic habitat and water quality protection, river quality monitoring, and fish habitat compensation. The pipeline crossing was successfully completed within the specified nine months' timeline and allocated budget. Some of the lessons learned during the project include adjustment of the construction sequence and the importance of hydraulic analysis and robust cofferdam erosion control.

Construction dewatering near environmentally sensitive locations require plans and techniques to ensure that no harm is done to the environment. Although construction dewatering is a component of the project that is typically considered a contractor's means and methods that the engineer and owner prefer not to control, the owner could be responsible for damages if the effort is mishandled. Construction dewatering plans may be needed if a project is in proximity to a salt water body, a site with contamination, or a wetland. Furthermore, downstream waters should be protected from turbidity and erosion that can result from construction activities, including construction dewatering. When these situations are encountered, the design engineer can employ various techniques to reduce those impacts in the construction documents including the following: hydraulic barriers, reduced quantity and duration of dewatering, environmental cleanup measures, onsite disposal areas, and monitoring.

A numerical modeling study was carried out to investigate the dynamic behavior and lateral earth pressures on box-shaped culverts buried in dry cohesionless soils. Two dimensional plane strain finite difference models of 4m-high prototype box culverts having different wall flexibilities were analyzed using FLAC-2D Finite Difference Code. Within the analyses, uniaxial input motions composed of harmonic excitations with amplitudes of 0.25 g and 0.40 g and frequencies of 2 to 15 Hz were applied to the numerical models. Box culvert sections with different wall thicknesses were analyzed to investigate the effect of relative flexibility on the dynamic response. Shear strains, horizontal accelerations, wall deformations, and lateral dynamic earth pressures at various points on the culvert were monitored. Racking deformations were calculated from displacement data obtained from the analyses. Results of the numerical analyses were validated with those of the centrifuge tests performed under 40-g centrifugal acceleration. Racking deformations of the analyzed culvert models are in good agreement with the test data. Racking curves for culverts having different flexibilities were estimated based on numerical modeling results. Good agreement exists between the actual data and those predicted with the finite difference method. Dynamic lateral pressures acting on the side walls increase as the wall flexibility ratio decreases. For the range of excitation characteristics, dynamic force on the sidewalls of the box culvert may reach up to 2.8 times the at-rest lateral stress for the stiff prototype.

The James City Service Authority (JCSA) provides municipal wastewater collection service to almost 19,000 customers within the Hampton Roads Sanitation District (HRSD) in Eastern Virginia. Both HRSD and JCSA, along with 12 other localities, entered into a consent decree with the EPA in February 2010 in an effort to prevent excessive discharges. Electro Scan, in conjunction with a local contractor, completed a pilot project within two different subbasins of particular concern. These basins were selected because in spite of multiple inspections using traditional examination methods and a preliminary rehabilitation effort, significant unidentified locations of rain-dependent infiltration (RDI) remained, as confirmed by flow monitoring. This presentation will describe the methods and results of the project and compare those to traditional inspection methods. It will also discuss how Electro Scan's ES-620 located and then objectively quantified the sources of RDI and helped JCSA prioritize its DEQ-required rehabilitation program.

Selection of sewer pipe material for a project is traditionally based on engineering principles and cost effectiveness. This approach typically does not factor in the upstream or downstream environmental or human health aspects of the sewer pipe material. Prompted by the City of Portland's Toxics Reduction Strategy (2006), Sustainable Procurement Policy (2008), Healthy Purchasing Initiative (2012), and related sustainability policies, the City's Bureau of Environmental Services (BES, "Bureau") began exploring the implications of including the environmental and human health impacts of pipe material into pipe selection decisions. In 2012 the BES contracted an independent consulting firm to review publicly available sewer pipe life cycle assessments (LCAs) to see if any conclusions could be made regarding which material (reinforced concrete, polyvinyl chloride, or vitrified clay pipe) is environmentally preferable. This paper discusses the findings of this review and how this exploration of the upstream and downstream environmental and human health impacts of sewer pipe material has fostered new discussions within BES regarding pipe material selection.

The City of Casselberry is nearing the end of its water quality improvement projects, which have utilized prechlorinated potable water main pipe bursting to replace approximately 35 mi (184,800 linear ft) of asbestos cement (AC) pipe. This project is likely the largest of its kind in the United States. The project has received $10.3 million in funding from the American Recovery and Reinvestment Act and the Florida Department of Environmental Protection's (FDEP) State Revolving Fund Program. The City, engineer, and contractor have worked very closely with FDEP and the Environmental Protection Agency (EPA) to determine the applicability of the National Emissions Standards for Hazardous Air Pollutants (NESHAP) to the fractured pieces of AC pipe remaining in the ground after the pipe bursting process. Utilization of pipe bursting over traditional open cut provides many environmental, social, and economical benefits to the City's customers and residents. This paper will describe the working process in place to burst AC pipe while meeting all EPA regulations and will describe all the efforts to complete the project.

This paper will explain AWWA pipeline standards and manuals of practice, what items they cover, how they are used in the industry, and how they are developed. North American engineers routinely use AWWA standards and manuals as the foundation for water and wastewater pipeline projects. This paper will demystify the use, content, and development of AWWA standards. The paper will detail the different types of pipe covered by AWWA standards and the associated standards for fittings, coatings, installation, rehabilitation, and disinfection. The paper will also address the typical industry applications covered. It will address the technical details of design, verification, and purchaser options that engineers should be aware of for successful use of AWWA standards in their projects. The relationship between standards and the accompanying manuals of practice and how to use each will be covered. Lastly, the paper will cover the consensus development process for AWWA standards and how anyone can participate in the process either through direct committee participation, or through open public review and comment. The consensus development process used by AWWA is accredited by the American National Standards Institute (ANSI) and provides for consensus development through fair due process, a balance of participating interests, and openness to all interested parties. To be designated as an American National Standard, the accredited consensus process must be followed and documentation of such reviewed and approved by ANSI.

Water transmission lines are vulnerable to adverse hydraulic transient phenomena that could occur due to flow control operations such as sudden valve opening or closure and sudden power failure of pumps. Hydraulic transients can cause pipe bursts, pipeline leakages, and water contamination, resulting in huge loss of assets and causing serious health risks. Pipelines carrying nonpotable treated sewage effluent (TSE) are only used for irrigation purposes in the Middle East region; therefore, pipe bursts or leakages from TSE transmission lines due to hydraulic transients can cause much more health risks than potable water transmission lines. Therefore, these transmission lines are primarily designed to control adverse transient events along with the consideration of cost effectiveness. In this study, surge analysis results of a 1,000-mm TSE transmission pipeline (having 16 bars pressure rating) are compared with respect to three different pipeline materials (glass fiber-reinforced plastics [GRP], high-density polyethylene [HDPE], and ductile iron [DI]). The transmission line originates from a pumping station having two pumps (each with a capacity of 270 L/s @ 80 m head) running in parallel. The transmission main is serving five irrigation reservoirs having a total TSE demand of 10.27 MIGD that are located at five different locations along its total length of 11.22 km. The most remote reservoir is located at 31 m higher elevation from the pump station at a distance of about 11.50 km. Transient analyses have been carried out considering a surge protection (selecting a vertical type surge vessel with a bladder) for three different pipe materials: GRP, HDPE, and DI. The results obtained from the analysis were compared for minimum and maximum transient pressures in the modeled pipeline. It was observed that for all three considered pipe materials, the maximum transient pressures were around 10 bars, which was less than the pressure rating of the pipe (i.e., 16 bars); however, with the provided surge protection, the GRP pipe had positive minimum transient pressures; while the minimum transient pressures for HDPE and DI pipes were negative. It was also noticed that the GRP pipeline transmission system had the least cost among the HDPE and DI pipeline transmission systems, which cost more than twice what the GRP transmission system cost. The aforementioned indicated that for the studied TSE transmission line, GRP pipelines were more effective in controlling hydraulic transients and were also more economical and cost effective than HDPE and DI pipelines.

The Oregon Legislature tasked the Oregon Seismic Safety Policy Advisory Commission to 1) assess the resilience of Oregon infrastructure to a magnitude 9.0 earthquake on the Cascadia Subduction Zone, 2) develop a recommended level of service (LOS) for each category of infrastructure 50 years out, and 3) develop recommendations to achieve that LOS. The goals are to protect lives and provide for rapid recovery following a Cascadia earthquake. This paper reports on the work done by the Water and Wastewater Task Group (W/WW Task Group), one of eight task groups active in the project. The Cascadia Subduction Zone Earthquake represents the highest seismic risk of any source zone in the state with potential damage due to tsunami, shaking, and permanent ground deformation (PGD). W/WW Task Group members, representing key water and wastewater systems from throughout the state, estimated the expected damage to their supply and distribution systems considering pipe and soil type. Expected damage to treatment facilities, pump stations, and storage tanks were estimated based on the type and date of construction, as influenced by historical building code changes. The W/WW Task Group members then estimated the time it would take to restore service as a function of the extent of damage and resources available for restoration. It was estimated that it would take one to three months to restore transmission facilities in the Valley. Comparing the expected and desired LOS, the W/WW Task Group then developed recommendations that could be implemented by the State Legislature to encourage mitigation and help close the resilience gap. One of the key recommendations is to require that seismic vulnerability assessments be conducted by every utility in the state as part of their water master plans.

The current version of American Water Works Association (AWWA) Manual M-11, Steel Pipe: A Guide for Design and Installation, was published in 2004. This is the 4^th edition of the manual. AWWA policy requires reviewing and updating manuals, such as M11, every seven years. Through the course of the previous editions, numerous topics were added to the manual. Many of these topics were just added to the last chapter. The revision currently underway will reorganize the manual to better accommodate this information. This paper will review the history of AWWA Manual M11 and present the new organization of the proposed revisions. Discussion of the changes will be presented. These include clarification of nomenclature and formulae and some guidance on seismic design.

The American Water Works Association's (AWWA) 2012 report, "Buried No Longer: Confronting America's Water Infrastructure Challenge," shows that the cost of repairing and expanding U.S. drinking water infrastructure will top $1 trillion in the next 25 years. The looming infrastructure challenges and the need for repair, replacement, and rehabilitation of vast amounts of water and wastewater pipeline infrastructure will require innovative ideas, practices, and products. Design practices of engineers and investment by utility purchasers for long-term infrastructure assets requires prudent and responsible consideration. Proven practices and products are often preferred over the unknown life expectancy of less mature technologies. Balancing innovation with historical practices is, and will continue to be, an ever-growing challenge for the water and wastewater community and the key decision makers in the industry. This paper covers the approaches that AWWA takes in standards development to recognize new technologies while maintaining a balance of adequate historical use and proven design. The paper includes examples from recent pipeline standard revisions and the ensuing debates over inclusion of newer technologies (ANSI/AWWA C605 on underground PVC pipe installation and ANSI/AWWA C906 on polyethylene pipe). The paper provides a better understanding of how new technologies are considered for AWWA standards, the criteria defined for standards, and the review process for consensus approval. The paper includes an invitation looking for feedback from the audience as to their ideas for balancing and accelerating innovation in the standards process.

In the summer of 2014, Schnitzer Steel (Schnitzer), in Oakland, California, will expand its railroad system, which will conflict with an existing East Bay Municipal Utility District (District) water main. In the past, the District would have relocated the main at the expense of Schnitzer. Given the unique aspects of the issue, a different, new approach was developed that benefitted both parties. The District historically had trouble maintaining the main due to accessibility issues, coupled with contaminated soils. When the District installed this main in the 1930s, this area was a thriving industrial area with the main installed in an accessible roadway. Over time, the land use changed. Many of the industries left the area, and the street alignment changed leaving the District with an inaccessible main. Because the main currently travels through the Schnitzer facility, Schnitzer's entire operation would be affected if a main break occurred. After months of negotiating, the parties decided that Schnitzer would pay for the relocation of its fire and domestic water meters and upgrade its water system to accommodate the meters' new location. The District would replace the main serving the Schnitzer facility but stop at the property line. This replacement used a jack-and-bore installation method. It required a detailed site layout because the Schnitzer facility could not be affected. This allowed the District to abandon a significant portion of a troublesome main and for Schnitzer to install its railroad system without water main interference. This approach is being implemented in other relocation and system improvement projects with difficult to maintain mains in inaccessible rights of way to reduce long-term operating costs.

In the recent past, rating systems for infrastructure in the United States were sector specific, and a single rating tool applicable to all the different infrastructure categories didn't exist until 2012, when Envision was released. Envision is an infrastructure rating system applicable to all infrastructure categories such as energy, water, waste, transportation, and information. Envision is a tool for evaluating and rating the social, economic, and environmental benefits of all types and size of civil infrastructure projects. Envision provides an objective framework to assess project sustainability, build sustainability awareness, and meet client requirements for project sustainability. Sustainability of civil infrastructure is critical to project owners, funding agencies, regulators, professionals, and the public. Envision guides practitioners, owners, and stakeholders in framing infrastructure solutions and performance goals. This paper discusses how the rating system assesses performances, recognizes achievements, and serves as a measure of infrastructure sustainability. Envision is more than a mere rating tool, a true path forward in advancing sustainability knowledge and education for future generations.

Energy efficiency is a critical consideration for all water infrastructure projects. This is especially true for large water transmission pumping systems in which the energy costs over the life of the installed equipment can be as much as five times that of the initial purchase price. Colorado Springs Utilities is currently constructing the Southern Delivery System (SDS) project, which includes more than 50 mi of water transmission pipeline, three large raw water pump stations, and a water treatment plant (WTP). To minimize life-cycle costs (LCCs), the pumps, motors, and variable frequency drives (VFDs) were procured using a unique LCC procurement strategy. Pumping equipment typically is procured by selecting the pump with the lowest initial purchase price that meets the performance criteria of the project. An engineer will specify a "design point" (flow and pressure condition) with a minimum efficiency based on a review of several candidate pumps that essentially describes the performance criteria. The "design point" frequently reflects flow and pressure under the most severe pumping conditions, which will occur infrequently during the life of the pump station. In contrast, the life-cycle procurement approach used for the SDS pumping equipment evaluated the initial purchase price along with the expected hydraulic conditions and weighed the value of each condition based on the expected frequency of occurrence. An effective LCC procurement strategy depends on an accurate forecast of future operational conditions. For the SDS, this forecast required close collaboration of SDS program staff with Colorado Springs Utilities' operations, engineering, and water resources staff. This close collaboration resulted in a detailed planning document known as the basis of operations (BOO), which included 30 years of monthly average day flow projections (360 data points) for the SDS system. An effective LCC procurement strategy also depends on procurement documents that are easy for a pump manufacturer to understand. Some manufacturers may be hesitant to respond to an overly complicated procurement package, which can reduce competition and potentially increase price. This paper will describe the unique procedures used to forecast future operational conditions, distill those conditions down to a discrete set of representative conditions, and evaluate candidate pump manufacturers' performance against those conditions to identify the equipment that represents the best value.

In this study, fracture and failure behavior of multilayered polymer composite used as thermal insulator in subsea pipe line was investigated at various strain rates (ε) with and without simulated cracks. For this study, polymer composites samples were obtained from field pipes used in the North Sea. The multilayered polypropylene composite materials were tested in four-point bending with and without notch at various displacement rates. Also the fracture behavior of the polymer composite materials was investigated in direct tension at various loading rates with and without pinholes. A 3D digital image correlation (DIC) system was used to monitor the deformation field near the crack tip, which provided the strain field distribution with the crack initiation and growth with time. The polymer composite material was viscoplastic and the tensile strength and failure strain increased and decreased respectively with the increasing strain rate. The tensile strain intensity factor γ (a new concept) was determined to govern the fracture behavior of the materials due to the strain concentration at the crack tip. In the range of strain rates (ε) investigated in this study, the strain intensity factor γ was over 30 for the unfilled polypropylene (PP) and polypropylene composite with 65% glass filler.